4.0 Work Zone Impacts Management Strategies
Many work zone impacts management strategies can be used to minimize traffic delays, improve mobility, maintain or improve motorist and worker safety, complete roadwork in a timely manner, and maintain access for businesses and residents. This section briefly describes various work zone management strategies, grouped according to the following categories:
- Temporary traffic control (TTC):
- Control strategies.
- Traffic control devices.
- Project coordination, contracting and innovative construction strategies.
- Public information (PI):
- Public awareness strategies.
- Motorist information strategies.
- Transportation operations (TO):
- Demand management strategies.
- Corridor/network management (traffic operations) strategies.
- Work zone safety management strategies.
- Traffic/incident management and enforcement strategies.
Table 4.1 presents various work zone management strategies by category. This set of strategies is not meant to be all-inclusive, but offers a large number to consider, as appropriate, in developing transportation management plans (TMPs). Individual strategies may fit into multiple categories. For example, changeable message signs (CMS) are a traffic control device defined in the Manual on Uniform Traffic Control Devices (MUTCD), and thus are included in this category. However, they are also frequently used for motorist information and are included in that category as well.
This section is intended to be a reference for selecting work zone management strategies as described in Section 2.2.1, Step 4 and Section 3.7 of this document. Agencies can look through Table 4.1 to get ideas for potential strategies, and then refer to the rest of the chapter for more information as needed. This section provides definitions for the strategies and is supported by Appendix B, which provides information helpful for determining when the strategies should be considered, pros/cons, and whether the strategies are likely to improve mobility and/or safety.
Several best practices associated with work zone management strategies can be found on the FHWA Work Zone web site at https://www.fhwa.dot.gov/workzones (Accessed 07/15/05). Benefits information for real-world applications and studies for some of the transportation operations and public information strategies is located in the Intelligent Transportation Systems (ITS) Joint Program Office Benefits Database at http://www.benefitcost.its.dot.gov/its/benecost.nsf/ByLink/BenefitsHome (Accessed 07/15/05).
|A. Control Strategies||B. Traffic Control Devices||C. Project Coordination, Contracting, and Innovative Construction Strategies|
IA1. Construction phasing/staging
IA2. Full roadway closures
IA3. Lane shifts or closures
IA4. One-lane, two-way operation
IA5. Two-way traffic on one side of divided facility (crossover)
IA6. Reversible lanes
IA7. Ramp closures/relocation
IA8. Freeway-to-freeway interchange closures
IA9. Night work
IA10. Weekend work
IA11. Work hour restrictions for peak travel
IA12. Pedestrian/bicycle access improvements
IA13. Business access improvements
IA14. Off-site detours/use of alternate routes
IB1. Temporary signs
IB2. Changeable message signs (CMS)
IB3. Arrow panels
IB4. Channelizing devices
IB5. Temporary pavement markings
IB6. Flaggers and uniformed traffic control officers
IB7. Temporary traffic signals
IB8. Lighting devices
IC1. Project coordination
IC2. Contracting strategies
IC3. Innovative construction techniques (precast members, rapid cure materials)
|A. Public Awareness Strategies||B. Motorist Information Strategies|
IIA1. Brochures and mailers
IIA2. Press releases/media alerts
IIA3. Paid advertisements
IIA4. Public information center
IIA5. Telephone hotline
IIA6. Planned lane closure web site
IIA7. Project web site
IIA8. Public meetings/hearings
IIA9. Community task forces
IIA10. Coordination with media/schools/businesses/ emergency services
IIA11. Work zone education and safety campaigns
IIA12. Work zone safety highway signs
IIA13. Rideshare promotions
IIA14. Visual information (videos, slides, presentations) for meetings and web
IIB1. Traffic radio
IIB2. Changeable message signs (CMS)
IIB3. Temporary motorist information signs
IIB4. Dynamic speed message sign
IIB5. Highway advisory radio (HAR)
IIB6. Extinguishable signs
IIB7. Highway information network (web-based)
IIB8. 511 traveler information systems (wireless, handhelds)
IIB9. Freight travel information
IIB10. Transportation management center (TMC)
|A. Demand Management Strategies||B. Corridor/Network Management Strategies||C. Work Zone Safety Management Strategies||D. Traffic/Incident Management and Enforcement Strategies|
IIIA1. Transit service improvements
IIIA2. Transit incentives
IIIA3. Shuttle services
IIIA4. Ridesharing/carpooling incentives
IIIA5. Park-and-ride promotion
IIIA6. High-occupancy vehicle (HOV) lanes
IIIA7. Toll/congestion pricing
IIIA8. Ramp metering
IIIA9. Parking supply management
IIIA10. Variable work hours
IIIB1. Signal timing/coordination improvements
IIIB2. Temporary traffic signals
IIIB3. Street/intersection improvements
IIIB4. Bus turnouts
IIIB5. Turn restrictions
IIIB6. Parking restrictions
IIIB7. Truck/heavy vehicle restrictions
IIIB8. Separate truck lanes
IIIB9. Reversible lanes
IIIB10. Dynamic lane closure system
IIIB11. Ramp metering
IIIB12. Temporary suspension of ramp metering
IIIB13. Ramp closures
IIIB14. Railroad crossings controls
IIIB15. Coordination with adjacent construction site(s)
IIIC1. Speed limit reduction/variable speed limits
IIIC2. Temporary traffic signals
IIIC3. Temporary traffic barrier
IIIC4. Movable traffic barrier systems
IIIC6. Temporary rumble strips
IIIC7. Intrusion alarms
IIIC8. Warning lights
IIIC9. Automated Flagger Assistance Devices (AFADs)
IIIC10. Project task force/committee
IIIC11. Construction safety supervisors/inspectors
IIIC12. Road safety audits
IIIC13. TMP monitor/inspection team
IIIC14. Team meetings
IIIC15. Project on-site safety training
IIIC16. Safety awards/incentives
IIIC17. Windshield surveys
IIID1. ITS for traffic monitoring/management
IIID2. Transportation management center (TMC)
IIID3. Surveillance [Closed-Circuit Television (CCTV), loop detectors, lasers, probe vehicles]
IIID4. Helicopter for aerial surveillance
IIID5. Traffic screens
IIID6. Call boxes
IIID7. Mile-post markers
IIID8. Tow/freeway service patrol
IIID9. Total station units
IIID11. Coordination with media
IIID12. Local detour routes
IIID13. Contract support for incident management
IIID14. Incident/emergency management coordinator
IIID15. Incident/emergency response plan
IIID16. Dedicated (paid) police enforcement
IIID17. Cooperative police enforcement
IIID18. Automated enforcement
IIID19. Increased penalties for work zone violations
Temporary traffic control strategies, devices, and contracting/construction techniques and coordination are used to facilitate traffic flow and safety through and around work zones. Standards, guidance, and other information defining the proper use of the traffic control strategies and devices are provided in Part 6 (Temporary Traffic Control) of the MUTCD and Chapter 9 (Traffic Barriers, Traffic Control Devices, and Other Safety Features for Work Zones) of the American Association of State Highway and Transportation Officials (AASHTO) Roadside Design Guide. Information on contracting and construction techniques is available from various references listed throughout this report.
This category includes various traffic control approaches used to accommodate road users within the work zone or the adjoining corridor in an efficient and safe manner, while providing adequate access to the roadway for the required construction, maintenance, or utility work to be performed.
IA1. Construction phasing/staging. Staging typically refers to how the contractor will position the equipment and materials. Phasing refers to the sequencing of the aspects of a project, completing portions of the project one part at a time. The impacts of a work zone on traffic may be minimized by using operationally-sensitive phasing and staging throughout the life of the project.
In Maine, the Department of Transportation has an agreement (constructability review agreement) with Associated Contractors of Maine to assist the State with developing construction-phasing options on selected high-risk projects. This is done prior to letting the project.
Source: Maine Department of Transportation
The Oklahoma DOT (ODOT) provides for contractor participation in constructability reviews for projects over $5 million by allowing all contractors to review plans in advance of advertisement. This allows ODOT to incorporate good design and construction ideas, prior to advertisement, which will result in more economical and quicker projects. Such early review by contractors also provides a way to detect errors overlooked in the design phase and allows contractors additional time to become more familiar with the project, enabling them to submit more accurate bids.
Source: FHWA Work Zone Best Practices Guidebook, April 2000, https://ops.fhwa.dot.gov/wz/practices/best/Default.htm (Accessed 08/18/05).
IA2. Full roadway closures. This strategy involves complete closure of the roadway for various time periods to minimize the duration of the project and improve worker safety by reducing traffic conflicts. Full closures may be brief (e.g., intermittent, off-peak), short-term (e.g., night, weekend), or long-term (e.g., continuous for the duration of the project).
Information on the application and benefits of full road closure during rehabilitation and construction for DOTs in Oregon, Kentucky, Michigan, Ohio, Washington, and Delaware are available in a report and case studies at https://ops.fhwa.dot.gov/wz/construction/full_rd_closures.htm (Accessed 07/15/05).
IA3. Lane shifts or closures. Lane shifts or closures last for varying durations of time. They may be intermittent, off-peak, night, weekend, for a single project phase, or continuous for the duration of the project. This strategy involves multiple approaches including:
- Reduced lane widths to maintain number of lanes (constriction). This involves reducing the width of one or more lanes in order to maintain the existing number of lanes on the facility while permitting work access to part of the facility.
- Lane closures to provide worker safety. This strategy closes one or more existing traffic lanes to accommodate work activities.
- Reduced shoulder width to maintain number of lanes. This involves reducing the width of the inside and/or outside shoulder to maintain the existing number of lanes on the facility while allowing access for the work activities to take place.
- Shoulder closures to provide worker safety. This strategy closes the shoulder for use by the public, making it available to accommodate the work activities.
- Lane shift to shoulder/median to maintain number of lanes. This strategy involves diverting traffic onto the shoulder, or a portion of the shoulder, for use as a traffic lane.
IA5. Two-way traffic on one side of divided facility (crossover). This strategy involves closing one side of a divided facility to permit the work to proceed without traffic interference while both directions of traffic are accommodated on the opposing side of the roadway.
IA6. Reversible lanes. This strategy, also known as variable lanes or contra-flow lanes, involves sharing lane(s) of travel to accommodate peak-period traffic flow. The direction of travel in the shared lane varies by time of day or day of the week.
IA7. Ramp closures/relocation. Ramp closure involves closing one or more ramps in or near the work zone for specific time periods or construction phases to allow work access or improve traffic flow on the mainline.
NCHRP Report 475 provides a process to help agencies determine whether to perform nighttime construction or maintenance.
Source: National Cooperative Highway Research Program, Report 475, A Procedure for Assessing and Planning Nighttime Highway Construction and Maintenance, 2002, URL: http://trb.org/publications/nchrp/nchrp_rpt_475.pdf (Accessed 07/27/05).
IA11. Work hour restrictions for peak travel. This involves restricting work hours such that work that impacts traffic does not occur during periods of peak travel demand and congestion (e.g., peak hours, holidays, special events).
IA12. Pedestrian/bicycle access improvements. This strategy involves providing alternate facilities for bicyclists and pedestrians (including those with disabilities in accordance with the Americans with Disabilities Act of 1990) in places where the work zone impacts their accessibility.
IA13. Business access improvements. Some projects will have a direct impact on businesses, particularly to accessibility. Accessibility improvements for businesses may include signage or information to direct motorists to the business(es) and/or relocation of access locations.
4.1.2 Traffic Control Devices
The MUTCD provides standards, guidelines, and other information pertaining to installing, maintaining, and operating traffic control devices on streets and highways. Part 6 of the MUTCD, "Temporary Traffic Control," addresses safety, mobility, and constructability issues in work zones, and is applicable to all types of highway work from major construction on high-volume freeways to minor maintenance on residential streets, and everything in-between. Traffic control devices and other safety devices used for work zones include:
IB1. Temporary signs. Several types of temporary signs can be used to provide information to road users to enable safe and efficient travel through the work zone or a detour. Temporary signs are an essential and integral part of temporary traffic control, and are used in nearly all work zones. Accepted practices for work zone signing are provided in the MUTCD, including Part 6 and various other references. Temporary signs typically include the following types:
- Warning. These signs give notice to road users of a situation that may not be readily apparent (e.g., speed reductions, road or lane narrows, etc.).
- Regulatory. Regulatory signs provide notice to road users of traffic laws or regulations through the work zone (e.g., speed limits, fine notices, parking restrictions, road closed, etc.).
- Guide/information. Advance signing and signing in and around the work zone area are used to notify the motoring public of the work zone and/or offer options for alternative routes. Signs may include dates and/or locations of construction and/or closures. Detour signs direct motorists onto detour routes, through the detour, and back to the route from which they were detoured. Advance notice is required so that motorists have time to choose an alternate route.
IB2. Changeable message signs (CMS). Both fixed and portable changeable message signs are highly effective in conveying work zone information to drivers, especially when that information is subject to frequent change or it addresses a short term or current situation or condition within the work zone. These signs provide real time information to drivers concerning specific work operations, traffic patterns, and other conditions in the work zone. These devices assist drivers in avoiding conflicts and potential crashes as they travel through the work zone.
IB4. Channelizing devices. This strategy involves the use of channelizing devices such as traffic cones, drums, barricades, or tubular markers for traffic control through the work zone. The purpose is to define the intended travel path through the work zone and delineate potential work zone hazards.
IB5. Temporary pavement markings. Various types of temporary markings on the pavement are available to define travel lanes and provide guidance and information for the road user through the work zone.
IB6. Flaggers and uniformed traffic control officers. Flaggers, and to a lesser extent police or traffic control officers, are used to direct and control road user and pedestrian traffic in work zones.
IB8. Lighting devices. A wide range of lighting devices, listed in Part 6 of the MUTCD, is available for use in work zones. Lighting strategies offer enhancement to other work zone strategies by attracting attention to the devices and improving delineation, particularly for adverse conditions. They can also be used for improved worker safety and for guiding road users through a work zone, particularly for night work.
General guidance for worker safety and visibility is provided in the FHWA Office of Safety Worker Safety and Visibility Brochure, available at http://safety.fhwa.dot.gov/wz/wzw5.htm (Accessed 07/15/05)
- Coordination with other projects. This involves coordinating, sequencing, and scheduling projects to minimize motorist delay and impacts to potentially affected businesses and communities.
- Utilities coordination. This involves coordinating and scheduling utility work both within the impacted work zone area and near the project to minimize potential work disruptions or interruptions due to utility work, and reduce overall construction duration. Coordination can also reduce the recurrence of work zones by doing two jobs together. For example, the installation of a communications conduit (for traffic management, ITS, etc.) along a highway corridor may coincide with a pavement reconstruction project on that highway.
In Phoenix, Arizona, design and construction of city water and sewer lines within the street right of way is done by the Street Transportation Department. Prior to the implementation of this policy, each entity designed and constructed their facilities in a separate project. This in effect resulted in the neighborhoods being torn up on three separate occasions to construct the project. By bringing all work under the Street Transportation Department, the work could all be accomplished in one contract thereby saving time, money, increasing safety, and having less impact and disruption to the community.
Source: FHWA Work Zone Best Practices Guidebook, April 2000, https://ops.fhwa.dot.gov/wz/practices/best/Default.htm (Accessed 08/19/05).
- Right-of-way coordination. Increased consideration of potential right-of-way needs and issues may help reduce project delays and duration.
- Coordination with other transportation infrastructure. Coordination with non-highway transportation facilities such as transit junctions, railroad crossings, and intermodal facilities can help minimize traffic disruptions.
- Design-build. This strategy involves the use of one contract to design and build the project thus reducing project duration by allowing construction to begin prior to design completion.
- A+B bidding. A+B bidding encourages contractors to minimize construction impacts by reducing construction time. Part A refers to the contractor's bid for the actual items of work, and Part B is the total of the number of days bid to complete the project multiplied by the daily road user cost stipulated in the contract. The combined values of the A and B portions determine the winning bid. The contractor's payment is based on both Part A and the actual number of days used under Part B.
- Incentive/disincentive clauses. This strategy involves the use of incentives and/or disincentives in the construction contract to minimize construction duration.
- Lane rental. Lane rental involves a charge assessed to the contractor when a portion of the roadway is obstructed and unavailable to traffic. The lane rental charge can vary according to time of day, day of week, number of lanes impacted, and duration. The contractor's bid includes an estimate of the number of hours that closures will be in place, with the actual payment to the contractor based on the actual use of closures.
IC3. Innovative construction techniques (precast members, rapid cure materials). These strategies involve the use of special materials such as quick curing concrete or precast items (e.g., culverts, bridge deck slabs, and pavement slabs) to minimize the duration of construction or maintenance activities where traffic restrictions need to be minimized (e.g., roadways with high volumes), and when work activities need to be completed during night or weekend periods to allow reopening travel lanes for normal weekday travel.
The inclusion of a public information component in the TMP has the potential to reduce work zone impacts by providing specific information concerning road projects to road users and the community to alert them to potential impacts and available means to avoid them, as well as more general information concerning appropriate driving and travel behavior and travel options associated with the work zone. Early public involvement, particularly by the impacted communities and businesses, in the development of the TMP and keeping them informed throughout the project, is essential both to identify potential impacts and to ensure that effective mitigation strategies are developed and implemented. Coordination with the agency's public information office will help to ensure success, particularly for significant projects. These strategies include both public awareness strategies and motorist information strategies.
"Based on our experience, public information is the TMP mitigation strategy that gives us the 'biggest bang for the buck' - its effectiveness is greater in urban areas, but still holds true in rural areas."
Source: Quote from Robert Copp, California Department of Transportation, used in Transportation Management Plans for Work Zones fact sheet (FHWA-HOP-05-022), URL: https://ops.fhwa.dot.gov/wz/resources/tmp_factsheet.pdf (Accessed 11/18/05).
Public awareness strategies include various methods to educate and reach out to the public, businesses, and the community concerning the road project and work zone:
IIA1. Brochures and mailers. Brochures and mailers are printed material containing project-related information such as advanced notice of the project's start date, schedules, pictures/graphics of the project, a description of the need for the project, alternative routes, etc. These may be passed out to motorists at key locations (e.g., large employers in the project area, rest stops, travel information centers), via automobile associations, or mailed to affected businesses or communities.
IIA2. Press releases/media alerts. This strategy provides project-related information to the news media, affected businesses, and other affected or interested parties using print and/or electronic media.
At the project level, Arizona uses a Construction Project Public Information/Public Relations Program where weekly newsletters are sent to the media, business, local residents, and others who request to be included. The newsletters typically provide information on project status, lane restrictions, ramp closures, recommended detour routes, access to area businesses, and other work zone traffic restrictions in effect for the next few weeks. This program is generally used for very large projects in urban areas; however, it has also been used for some rural projects.
Source: FHWA Work Zone Best Practices Guidebook, April 2000, https://ops.fhwa.dot.gov/wz/practices/best/Default.htm (Accessed 07/15/05).
IIA3. Paid advertisements. Paid announcements of an upcoming major project may use newspaper, radio, and television ads, as well as billboards. Paid advertisements can also be used for progress updates or to provide information regarding major changes to the work zone configuration and management approach.
IIA4. Public information center. This is a facility typically located on or near the project site that contains such materials as scale model displays, maps, brochures, videos, etc. describing the project, its potential impacts, and available alternatives to minimize the impacts.
IIA5. Telephone hotline. This traveler information system provides traffic or travel information for the work zone using a toll-free telephone number. It can include prerecorded messages and/or real-time interactive request and response information.
IIA6. Planned lane closure web site. This strategy is typically not for one specific project, but is usually implemented for an entire State, district, or geographic region. The web page summarizes planned lane closures for public information, listing the routes involved as well as the closure start and end dates, both in text and graphical form.
IIA7. Project web site. This traveler information system provides traffic or travel information for the work zone via the web/Internet. It can include both long term static information and/or real-time interactive information.
IIA8. Public meetings/hearings. This strategy involves the presentation of project information to the public, community, and/or businesses by public relations staff, and solicitation of input concerning potential concerns, impacts, and management strategies.
IIA9. Community task forces. This strategy involves the development of community task force(s), which includes various stakeholders from the community likely to be impacted by the work zone (businesses, neighborhood groups, interested individuals, public officials, or other representatives). Task forces can be a means of both providing information and receiving input related to a road project.
IIA10. Coordination with media/schools/businesses/emergency services. This strategy involves coordinating with various community, business, and media groups that are likely to be impacted by the work zone, or that can disseminate needed information. Examples of these groups include local/cable TV newsrooms, schools and school districts, local major employers/businesses, and local emergency services (fire, police, and ambulance). Various mechanisms such as fax, e mail, phone message, mailings, etc. can be established to communicate project-related information including start dates, project schedules, significant traffic pattern changes, and traffic crashes and incidents within the work zone.
IIA11. Work zone education and safety campaigns. This strategy involves improving the awareness of motorists and/or increasing worker training in order to reduce the number of fatalities and injuries in work zones. This can be accomplished through brochures, web sites, media campaigns (radio, television), and videos.
IIA14. Visual information (videos, slides, presentations) for meetings or for web-based dissemination. This involves the use of videos, slides, and presentations to supplement public meetings, public information center displays, or press releases.
The Tennessee Department of Transportation (TDOT) implemented a highway work zone program designed to improve traffic flow and safety in construction areas. The plan is called Merge Left.
Source: http://www.tdot.state.tn.us/news/2005/040405.htm (Accessed 07/15/05).
These strategies provide current and/or real-time information to road users regarding the project work zone. Motorist information strategies include:
IIB2. Changeable message signs (CMS). These are fixed or portable message boards placed along roadways to notify road users of lane and road closures, work activities, incidents, potential work zone hazards, queues and slowed or stopped traffic ahead, and travel time or delay information, as well as alternate routes in or around the work zone. CMS can be placed at key locations before potential diversion points to give motorists an opportunity to divert to an alternate route or take other appropriate measures based on the information provided. As an enforcement tool, these signs can be used to inform drivers of speed limit reductions and enforcement activities in a work zone.
IIB3. Temporary motorist information signs. Temporary conventional signs mounted in the ground, overhead, or on vehicles to provide traveler information to guide motorists through the work zone and warn of potential hazards.
IIB4. Dynamic speed message sign. This portable system can be mounted as a fixed sign or located on a portable trailer. Radar measures the speed of approaching vehicles, which is displayed on the sign along with or near the work zone speed limit. The objective of this system is to enhance safety by reducing speeding and speed variations.
IIB5. Highway advisory radio (HAR). Longer, more detailed messages than can be provided using signage may be necessary for some work zone situations. HAR involves the dissemination of information to motorists while en route over wide-area wireless communications directly to in-vehicle radios. Signs are used to inform motorists of the radio frequency where the information is available.
Arkansas used an Automated Work Zone Information System (AWIS) in a rural work zone involving a central system controller, two HAR, five traffic sensors, five CMS, and two supplemental speed stations per lane closure. This system was designed to manage speed variability approaching the work zone, and to provide work zone information and delay times to travelers via CMS and HAR. The objective was to reduce the number of rear-end and fatal crashes at the site. An interview with the engineer responsible for overseeing the work zone construction indicated that the AWIS appeared to prevent/reduce rear-end collisions as long as traffic was not backed up past the CMSs.
Source: U.S. Department of Transportation, ITS Joint Program Office, Benefits Database, URL: http://www.benefitcost.its.dot.gov/its/benecost.nsf/ByLink/BenefitsHome (Accessed 07/15/05 ).
IIB6. Extinguishable signs. Extinguishable signs are typically associated with highway advisory radio (HAR) systems where the sign indicates how to obtain information on roadway conditions (e.g., tune in to 1610 AM). These signs turn on and off depending on when the HAR has a message available.
IIB7. Highway information network (web-based). A highway information network is a web site where multiple stakeholder groups can place information related to the roadway. The web site is shared among the various stakeholder groups, each with their own data storage areas (including control of functionality, security, data quality, etc.).
IIB8. 511 traveler information systems (wireless, handhelds). This strategy provides motorists with work zone-related information, static (e.g., project dates) and/or real time (e.g., potential delays), using such technology as cell phones, pagers, in-vehicle systems, and e mail notifications.
IIB9. Freight travel information. This strategy may be appropriate when there is a moderate to high percentage of freight movement through the work zone. It involves coordination with the freight community (trucking companies, truck drivers, etc.) to identify work zone information considered useful (e.g., truck restrictions, occurrences of incidents, planned closures, etc.) and development of a mechanism to disseminate that information to freight stakeholders. The information can be disseminated to central locations (e.g., via a fax or email distribution list to trucking companies) or to truckers as they approach the work zone (e.g., via CB communications tools such as the CB Wizard Alert System.)
The Wizard CB Alert System is a device that continuously broadcasts, over CB radio, a message that warns approaching drivers of the work zone ahead. The information can be broadcast over any selected CB channel, but since most truckers listen to channel 19, broadcasting over that channel means truckers generally have to take no action to receive the message.
The Smart Work Zone Deployment Initiative, a pooled-fund study in which researchers investigate better ways of controlling traffic through work zones and improving the safety and efficiency of traffic operations and highway work, has completed several evaluations of the Wizard CB Alert System. The findings have shown that truckers tend to find the system effective at alerting them to a work zone ahead so they can be prepared for altered conditions, such as lane closures, that may require them to change lanes or reduce speed.
Source: Smart Work Zone Deployment Initiative Pooled Fund Study, URL: http://www.ctre.iastate.edu/smartwz/index.cfm (Accessed 10/3/05).
The Oregon Department of Transportation's (ODOT) QuickFax service provides commercial truckers with up-to-the-minute information on closures and traffic delays on Oregon State highways. With this service, bulletins are faxed to approximately 154 trucking companies and 30 truck stops to inform them of immediate traffic delays related to incidents or weather. The service's subscriber base reaches truck stops as far away as Virginia, Nebraska, Wyoming, and California, so truckers heading into Oregon from those locations can have advance warning of any long-term road closures.
Source: U.S. Department of Transportation, Federal Highway Administration, "Fact Sheet 1 - Oregon's QuickFax Service", URL: https://ops.fhwa.dot.gov/wz/practices/factsheets/factsheet1.htm (Accessed 10/3/05).
IIB10. Transportation management center (TMC). This strategy involves the use of a TMC for coordinating and managing road user information dissemination activities. Often an existing TMC for the region is utilized and may be staffed by either contract staff and/or agency personnel. If the project is large and of long duration, a project specific TMC may be established and operated to help manage incidents and maintain traffic flow.
Transportation operations strategies are used to mitigate work zone impacts through the use of improved transportation operations and management of the transportation system. TO strategies typically include demand management, corridor/network management, work zone safety management strategies, and traffic/incident management and enforcement strategies.
Demand management strategies include a wide range of techniques intended to reduce the volume of traffic traveling through the work zone by such means as diverting travelers to alternate modes, shifting trips to off-peak hours, or shifting vehicles to alternate routes. These strategies include:
IIIA1. Transit service improvements. Where appropriate, transit service improvements may include the modification of transit schedules and/or routes, increases in frequency, or the establishment of transit service in the corridor.
IIIA4. Ridesharing/carpooling incentives. This strategy involves the use of rideshare/carpool incentives to reduce the number of vehicles traveling through a work zone. Incentives may include preferential parking for carpools, the addition of mainline HOV lanes or bypass lanes on ramps, provision of vanpool vehicles, etc.
The Woodrow Wilson Bridge project in Virginia and Maryland developed a program called "Bridge Bucks" which provides a $50 a month incentive to use transportation alternatives for commuters affected by the construction. Bridge Bucks can be applied to rail, bus, and organized vanpools.
Source: http://www.wilsonbridge.com/cms/cms-commuter-bb.htm (Accessed 07/15/05).
IIIA5. Park-and-ride promotion. This involves the creation, expansion, and/or promotion (advertising) of park-and-ride lots to encourage ridesharing or transit use, thus reducing the number of vehicles traveling through the work zone.
IIIA6. High-occupancy vehicle (HOV) lanes. HOV lanes, also known as carpool lanes, require two or more persons per vehicle for use (exceptions may include motorcycles and/or low emission vehicles). HOV lanes are intended to provide an incentive for carpooling.
IIIA7. Toll/congestion pricing. Tolls involve fees paid by motorists to drive on a particular roadway. Congestion pricing, or value pricing, is intended to reduce peak-period vehicle trips through the use of higher tolls during congested conditions.
IIIA8. Ramp metering. Ramp meters are traffic signals located on on-ramps or freeway connectors to maintain safe and smooth freeway operations by controlling the entry of vehicles onto the roadway. This strategy serves both to decrease demand on a facility by controlling the entrance of vehicles, and to improve flow by matching entering vehicles to gaps in the traffic stream.
IIIA10. Variable work hours. This strategy involves encouraging motorists who typically travel through the work zone during periods of high demand to work variable hours (off-peak) in order to reduce travel demand during peak periods.
IIIA11. Telecommuting. Telecommuting means working at home, or at a telecommuting center near home, either full or part time. Motorists who normally travel through the work zone would be encouraged to telecommute for the duration of the project to reduce the demand.
This category includes strategies to optimize traffic flow through the work zone corridor and adjacent roadways using various traffic operations techniques and technologies, including:
IIIB1. Signal timing/coordination improvements. This involves retiming traffic signals to increase throughput of the roadway(s), improve traffic flow, and optimize intersection capacity in and around the work zone.
IIIB2. Temporary traffic signals. The installation of temporary traffic signals can be used to improve traffic flow through and near the work zone. At a corridor or network level, using temporary traffic signals is more effective than stop signs or flaggers for providing mobility through the work zone area. These temporary traffic signals may also be coordinated with existing signals (see strategy IIIB1).
IIIB3. Street/intersection improvements. Improvements on streets and intersections for the roadway and/or alternate routes may be necessary to provide increased capacity to handle the traffic through the work zone or within the adjacent corridor. This may include improvements to the mainline and intersections, including roadway and/or shoulder widening and additional through and/or turn lanes.
IIIB4. Bus turnouts. This involves the construction of bus stop areas that are recessed from the travel lanes. This strategy may be helpful in work zones or on detour routes with a high occurrence of bus traffic and stops.
IIIB5. Turn restrictions. This involves restricting turn movements for driveways and/or intersections to increase roadway capacity, reduce potential congestion and delays, and improve safety. Restrictions may be applied during peak periods or all day.
IIIB6. Parking restrictions. This strategy involves the elimination of parking in all or part of the work zone and/or alternate routes, or parking restrictions during work hours or peak traffic periods. Parking restrictions can be used to increase capacity by converting the parking lane to an additional travel lane, reduce traffic conflicts, or provide improved access to the work area.
IIIB7. Truck/heavy vehicle restrictions. This strategy, which imposes restrictions on truck travel through the work zone either during specific periods or at all times, can increase passenger vehicle capacity of the roadway when a facility normally has a high truck volume. When using this strategy, the requirements of 23 CFR Part 658.11 (d) (1) and (g) must be followed.
IIIB8. Separate truck lanes. This strategy involves the provision of a separate truck lane through the restricted use of an existing lane, use of the shoulder or median, or construction of a new lane.
IIIB9. Reversible lanes. This strategy, also known as variable lanes or contra-flow lanes, involves sharing lane(s) of travel to accommodate peak period traffic flow. The direction of travel in the shared lane varies by time of day or day of the week.
IIIB10. Dynamic lane closure system. Also called dynamic lane merge system. This system uses dynamic electronic signs and other special devices to control vehicle merging at the approach to lane closures.
Intelligent Transportation Systems in Work Zones: A Case Study. Dynamic Lane Merge System - Reducing Aggressive Driving and Optimizing Throughput at Work Zone Merges in Michigan (FHWA-HOP-04-033) (2004) evaluates the use of a dynamic lane merge (DLM) system.
Source: https://ops.fhwa.dot.gov/wz/technologies/michigan/index.htm (Accessed 07/15/05).
IIIB11. Ramp metering. Ramp meters are traffic signals located on on-ramps or freeway connectors to maintain safe and smooth freeway operations by controlling the entry of vehicles onto the roadway. This strategy serves both to decrease demand on a facility by controlling the entrance of vehicles, and to improve flow by matching entering vehicles to gaps in the traffic stream. Various strategies for ramp metering include pre-set timing, traffic actuated (metering changes based on mainline traffic), or centrally controlled. Ramp metering may be used during peak periods or all day.
IIIB13. Ramp closures. Ramp closure involves closing one or more ramps in or around the work zone. The ramp closure may be necessary to provide work access within the work space or can be used to improve traffic flow on the mainline.
IIIB14. Railroad crossings controls. When a rail crossing is located within a work zone and/or on a detour or diversion route, traffic control improvements at the crossing may become necessary for safety purposes, especially if work zone delays and congestion have the potential to force vehicles to stop on the tracks or between the crossing gates. Improvements may include advanced warning signs, railroad crossing signs, pavement markings, flashing lights, gate arms, flaggers or police officers, and possibly closure of the crossing to traffic during work periods.
IIIB15. Coordination with adjacent construction site(s). This involves combining or coordinating projects within a specific corridor to minimize the combined impacts on the motoring public and community. Coordination typically involves scheduling projects within a corridor to ensure that adequate capacity remains available to accommodate the anticipated travel demand within the corridor by not implementing work zones on adjacent or parallel highways at the same time. This may entail communicating about the timing of lane closures and occurrence of incidents, and coordinating diversion routes. It may also involve the completion of needed capacity and safety improvements on a highway prior to its use to carry traffic diverted or detoured from another project.
Oklahoma found that many adjacent and alternate routes were being rehabilitated at the same time causing motorist delays. They are now making efforts to coordinate State DOT, local government, utility construction, and maintenance work.
Source: FHWA Work Zone Best Practices Guidebook, April 2000, https://ops.fhwa.dot.gov/wz/practices/best/Default.htm (Accessed 07/15/05).
This category includes devices, features, and management procedures used to address traffic safety concerns in work zones. Work zone safety management strategies include:
IIIC1. Speed limit reduction/variable speed limits. A reduced speed limit may improve traffic safety in a work zone and help protect workers. Speed limit reductions may be implemented through an entire work zone, or only in active work areas or adjacent to workers. Reduced speed limits may also be appropriate on detours where traffic volumes and conflicts are increased.
Information on variable speed limit applications and safe speeds in work zones is provided on the FHWA Office of Safety Speed Management web site, available at http://safety.fhwa.dot.gov/speed_manage/index.htm (Accessed 08/19/05).
IIIC2. Temporary traffic signals. This involves the installation of temporary traffic signals to address safety concerns. In some work zones, temporary traffic signals can be used in place of traffic control officers or flaggers, which can increase safety by removing these personnel from the roadway.
IIIC3. Temporary traffic barrier. Temporary traffic barriers provide positive physical separation between travel lanes and the adjacent work space, or between opposing travel lanes. Screens may be mounted on the top of temporary traffic barriers to discourage gawking and reduce headlight glare.
IIIC4. Movable traffic barrier systems. This system consists of a mechanical transfer machine, which quickly shifts temporary barrier laterally up to the full width of a travel lane while both the transfer operation and traffic in the work zone are protected. This system permits the rapid and safe reconfiguration of the traffic barrier system, allowing daily opening and closing of lanes for reversible lane operations and to provide additional space for the contractor to work during off-peak conditions.
IIIC5. Crash-cushions. Also known as an impact attenuator, a crash cushion is a fixed or mobile barrier used to protect a temporary hazard or prevent vehicle intrusion into the workspace or other hazardous area. It works by gradually decelerating the vehicle to a stop or by redirecting the vehicle away from the hazard.
IIIC6. Temporary rumble strips. Rumble strips are grooves or raised strips placed across or adjacent to a travel lane to alert motorists to a change in roadway conditions, or that they have strayed out of the travel lane.
The Ohio Department of Transportation uses rumble strips placed across the travel lane(s) approaching a long-term work zone to alert motorists of the construction zone.
Source: FHWA Work Zone Best Practices Guidebook, April 2000, https://ops.fhwa.dot.gov/wz/practices/best/Default.htm (Accessed 07/15/05).
IIIC7. Intrusion alarms. This strategy involves the use of various types of sensors to detect vehicles that stray out of the travel lane approaching or adjacent to the workspace and into the work area. When an intrusion is detected, a loud siren and/or flashing lights provide a warning to workers.
IIIC8. Warning lights. Various types of warning lights, as described in the MUTCD, are available to alert drivers and pedestrians and draw attention to critical signs, channelizing devices, and other work zone features.
IIIC9. Automated Flagger Assistance Devices (AFADs). AFADs are portable traffic control systems that assist a flagger operation for short-term lane closures, on two-lane highways. For a typical flagging operation with AFADs, one or both flaggers can be positioned a short distance away from the roadway and moving traffic. A flagger(s) can operate an AFAD(s) by using a radio control unit or an attached cable.
IIIC11. Construction safety supervisor/inspectors. Daily inspection and supervision of safety and/or traffic control operations is an integral part of project management, and can be provided by various contractor and/or agency personnel, as appropriate to their specific project responsibilities.
IIIC12. Road safety audits. Road safety audits involve analysis of the future or existing roadway by an independent expert on safety issues. It is a proactive way to reduce crashes and identify potential safety hazards. Audits may be performed during any stage of a road project, including planning, preliminary design, detailed design, traffic control planning, construction, pre-opening, and on existing roads.
IIIC13. TMP monitor/inspection team. This strategy involves the establishment of a team (or person) to monitor and inspect implementation and monitoring of the work zone transportation management strategies.
IIIC15. Project on-site safety training. This strategy provides on-going safety training to ensure that workers are familiar with safety procedures and specific risks associated with the project, and to maintain a high level of safety awareness.
Minnesota DOT has a Work Zone Safety Award Program for contractors and DOT employees that recognizes contractors and public agency personnel who have put forward outstanding work zone safety efforts on construction projects. This program has resulted in a positive impact toward improving work zone worker safety consciousness.
IIIC17. Windshield surveys. This strategy involves a designated DOT employee and/or contractor driving through the work zone area to conduct a firsthand assessment of safety and/or traffic flow. This strategy provides periodic assessments of the effectiveness of project safety features.
This category includes various strategies to manage work zone traffic operations. Work zone traffic management strategies involve monitoring traffic conditions and making adjustments to traffic operations based on changing conditions. Some of those changing conditions involve traffic incidents, so this category also looks at management strategies that have specific applicability to traffic incidents. These strategies involve improved detection, verification, response, and clearance of crashes, mechanical failures, and other incidents in work zones and on detour routes. This category also includes strategies to provide adequate enforcement of traffic regulations in work zones. Strategies in this area include:
IIID1. ITS for traffic monitoring/management. ITS can be used in work zones to identify areas where traffic flow is impeded so that traveler information can be provided and/or adjustments to the work zone can be made. A work zone ITS deployment uses sensors to detect traffic conditions and can automatically feed this information to motorist information outlets such as CMS and websites, or to a TMC. Monitoring traffic cameras can help detect places where drivers are having difficulty negotiating a work zone and then the layout can be adjusted.
IIID2. Transportation management center (TMC). This strategy involves the use of a TMC for coordinating and managing traffic and incident management activities in and around the work zone. Often an existing TMC for the region is used and may be staffed by either contract staff and/or agency personnel. If the project is large and of long duration, a project specific TMC may be established and operated to help manage incidents and maintain traffic flow.
IIID3. Surveillance [Closed-Circuit Television (CCTV), loop detectors, lasers, probe vehicles]. This strategy involves the use of surveillance equipment, such as detector stations or cameras, to help identify traffic problems and to detect, verify, and respond to incidents in the work zone.
IIID5. Traffic screens. Traffic screens help prevent driver distractions in work zones, which can help to keep traffic moving and enhance safety. Screens may be mounted on the top of temporary traffic barriers to discourage gawking and reduce headlight glare.
IIID6. Call boxes. Temporary or permanent call boxes may be installed through the work zone to provide motorists with a means to contact incident response personnel, thus expediting the response and clearance times for crashes and breakdowns.
IIID7. Mile-post markers. Mile-post markers consist of a sign located in the median or shoulder, which lists location information (direction, route, mile, and tenths of a mile). Some areas may refer to these as location reference markers, since they can be used to mark direction; route, bridge or overpass names; intersection names; etc. in addition to mileage information.
IIID8. Tow/freeway service patrol. This strategy involves the use of dedicated or on-site (or near site) towing services to reduce the time required to remove vehicles involved in an incident (breakdown or crash). Towing service is almost always contracted, while freeway service patrols might be contracted but are more likely to be publicly operated.
IIID9. Total station units. This involves the use of survey equipment for documenting/mapping major incidents (e.g., fatal crashes, HAZMAT conditions, etc.) in order to reduce the clearance time. In some locations, total station units are being replaced by laser measuring units.
IIID10. Photogrammetry. Photogrammetry involves the use of photos taken in the field and computer software for documenting and measuring incident-related data (e.g., skid marks, vehicle location, etc.) which may reduce incident clearance times.
The Utah Highway Patrol has reduced their average clearance time from an average of 60 to 90 minutes when total stations are used to 35 minutes with photogrammetry.
Source: Texas Department of Transportation, Use of Photogrammetry for Investigation of Traffic Incident Scenes, October 2000, URL: http://tti.tamu.edu/documents/4907-2.pdf (Accessed 08/18/05).
IIID11. Coordination with media. This strategy involves working with local news media to publicize traffic delays, incidents, and incident management. Working with media contacts in advance to establish procedures to be followed in the event of a major delay or incident can facilitate the dissemination of specific information upon the occurrence of a major delay or incident.
IIID12. Local detour routes. Advance identification and approval/authorization of local detour routes is an especially useful strategy to address major traffic delays and incidents, particularly for high volume and incident prone work zones.
IIID13. Contract support for incident management. This strategy provides additional contract support for incident management and response beyond that available from the construction contractor or within the agency. Contracts may include entities such as police agencies, towing/recovery providers, engineering consultants, or others, depending on the support needed for a project.
IIID14. Incident/emergency management coordinator. This strategy provides a designated individual with overall responsibility for incident and emergency management on a project. Responsibilities may include developing incident and/or emergency response plans, overseeing implementation and monitoring of the work zone management strategies, and overall management of incidents or emergencies.
IIID15. Incident/emergency response plan. This involves the development of a plan with information needed to respond to an incident. This information typically includes roles and responsibilities, response agencies, processes/procedures, actions to take for various incident types and levels, contact information, alternate routes, personnel and equipment information, staging area locations, and other information as appropriate to the individual project.
IIID18. Automated enforcement. Automated enforcement involves the use of various technologies such as radar, cameras, video, and sensors to detect and record vehicle speed or traffic signal violations. When a vehicle speed exceeds a specified threshold or a red signal violation occurs, the vehicle's license plate and/or driver are photographed. The citation with the photo(s) is then mailed to the registered owner of the vehicle.
IIID19. Increased penalties for work zone violations. This strategy involves the imposition of increased penalties for speeding or other violations in work zones. Such penalties include increased fines, increased points, license suspension, and even mandatory prison terms for serious violations.
- See Appendix B for information helpful in determining when these strategies should be considered, pros and cons, and whether the strategy tends to improve mobility, motorist safety, and/or worker safety.
- A range of other safety devices are described in Part 6 of the Manual on Uniform Traffic Control Devices (MUTCD) and are widely used to enhance safety and mobility in highway work zones. These devices, such as temporary traffic barriers and crash cushions, are included in the Work Zone Safety Management Strategies category.
- A range of other safety devices are described in Part 6 of the Manual on Uniform Traffic Control Devices (MUTCD) and are widely used to enhance safety and mobility in highway work zones. These devices, such as temporary traffic barriers and crash cushions, are included in the Work Zone Safety Management Strategies category (Section 4.3.3).
- 23 CFR Part 658, Truck Size and Weight, Route Designations - Length, Width and Weight Limitations, URL: http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=d29ba0f1f467909a35cf9e35171e60d2&rgn=div5&view=text&node=23:220.127.116.11.32&idno=23
- This footnote has been removed due to an inactive reference. (6/22/15).
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