Guide for Highway Capacity and Operations Analysis of Active Transportation and Demand Management Strategies
Appendix L: Designing an ATDM Program
ATDM strategies are combined into an overall ATDM program for addressing challenges to the efficient operation of the highway system. The ATDM program will have different plan elements to address specific challenges to the system.
- The travel demand management element (TDM) will address how demand management will be used to address recurring congestion on the facility.
- The weather traffic management plan element (W-TMP) will identify the ATDM strategies to be employed during weather events. The W-TMP will have a TDM component targeted to special weather events.
- The traffic incident management (TIM) element will identify the ATDM strategies to be employed for incidents. The TIM will have a TDM component to manage demand on the facility during incidents.
- The work zone traffic maintenance plan (WZ-TMP) element will identify the ATDM strategies to be employed for work zones. The WZ-TMP will have a TDM component to manage demand while work zones are present.
- Facilities located next to major sporting and entertainment venues may also have a special event management plan with ATDM strategies identified to support management of traffic before and after major events.
The FHWA web site, Travel Demand Management Toolbox (FHWA), provides resources to help manage traffic congestion by better managing demand. These resources include publications, web links, and training offerings.
According to the FHWA publication, Mitigating Traffic Congestion (Association for Commuter Transportation, 2004), demand management strategies include:
- Technology accelerators;
- Real time traveler information;
- National 511 Phone number;
- Electronic payment systems;
- Financial incentives;
- Tax incentives;
- Parking cash-out;
- Parking pricing;
- Variable pricing;
- Distance-based pricing;
- Incentive reward programs;
- Travel time incentives;
- High-occupancy lanes;
- Signal priority systems;
- Preferential parking;
- Marketing and education;
- Social marketing;
- Individualized marketing;
- Mode targeted strategies;
- Guaranteed ride home;
- Transit pass programs;
- Shared vehicles;
- Departure time targeted strategies;
- Worksite flextime;
- Coordinated event or shift scheduling;
- Route targeted strategies;
- Real-time route information;
- In-vehicle navigation;
- Web-based route-planning tools;
- Trip reduction targeted strategies;
- Employer telework programs and policies;
- Compressed work week programs;
- Location design targeted strategies
- Transit-oriented development;
- Live near your work; and
- Proximate commute.
The Mitigating Traffic Congestion guide should be consulted for more information on designing the TDM element of an ATDM program.
Weather Responsive Traffic Management (WRTM) involves the implementation of traffic advisory, control, and treatment strategies in direct response to, or in anticipation of, developing roadway and visibility issues that result from deteriorating or forecasted weather conditions (Gopalakrishna, Cluett, Kitchener, & Balke, 2011).
Weather responsive traffic management strategies include:
- Motorist advisory, alert and warning systems;
- Speed management strategies;
- Vehicle restrictions strategies;
- Road restriction strategies;
- Traffic signal control strategies;
- Traffic incident management;
- Personnel/asset management; and
- Agency coordination and integration.
FHWA’s report, Developments in Weather Responsive Traffic Management Strategies (Gopalakrishna, Cluett, Kitchener, & Balke, 2011) should be consulted for additional information on the design and selection of weather responsive traffic management strategies.
FHWA’s, Traffic Incident Management Handbook, (Owens, et al., 2010) provides information on the design of traffic incident management plans.
Traffic incident management (TIM) is “the coordinated, preplanned use of technology, processes, and procedures to reduce the duration and impact of incidents, and to improve the safety of motorists, crash victims and incident responders.” An incident is “any nonrecurring event that causes a reduction in capacity or an abnormal increase in traffic demand that disrupts the normal operation of the transportation system (Balke, 2009). Such events include traffic crashes, disabled vehicles, spilled cargo, severe weather, and special events such as sporting events and concerts. ATDM strategies may be included as part of an overall incident management plan to improve facility operations during and after incidents.
An agency’s incident management plan documents the agency’s strategy for dealing with incidents. It is, in essence, a maintenance of traffic plan (MOTP) for incidents, unplanned work zones. The responses available to the agency are more limited for incident management, and by definition, must be real time, dynamic responses to each incident as it presents itself. The agency’s incident maintenance of traffic plan (I-MOTP) ensures that adequate resources are prepositioned and interagency communications established to respond rapidly and effectively to an incident. The TIM plan may include measures in effect 24 hours a day, 7 days a week, weekdays only, weekday peak periods, or any other period of time or days of the week that are the focus of the incident management plan.
Incidents Defined and Classified
An incident is an unplanned disruption to the capacity of the facility. Incidents do not need to block a travel lane to disrupt the capacity of the facility. They can be a simple distraction within the vehicle (spilling coffee) or off on the side of the road or the reverse direction of the facility.
Incidents can be classified according to the response resources and procedures required to clear the incident. This helps in identifying strategic options for improving incident management.
The 2009 Manual on Uniform Traffic Control Devices (MUTCD) (FHWA) classifies incidents according to their expected duration (see section 6I.01 of the 2009 MUTCD).
- “Extended” duration incidents are those that are expected to persist for over 24 hours and should be treated like work zones (Section 6I.01 of MUTCD).
- “Major” incidents have expected durations of over 2 hours.
- “Intermediate” incidents have expected durations of 0.5 hours up to and including 2 hours.
- “Minor” incidents are expected to persist for less than 30 minutes.
Stages of Incident Management
Incident management is the systematic approach, planned, and coordinated use of human, institutional, mechanical, and technical resources to reduce the duration and impact of incidents. There are several stages to incident management:
- Motorist information;
- Site management:
- Traffic management;
- Investigation; and
Detection is the first notice that the agency receives that there may be an incident on the facility. Detection may occur via 911 calls, closed circuit TV cameras or detector feeds to a TMC, or maintenance/enforcement personnel monitoring the facility.
Verification confirms that an incident has occurred, collects additional information on the nature of the incident, and refines the operating agency’s understanding of the nature, extent, and location of the incident for an effective response.
A response is selected after an incident is verified and the appropriate resources are dispatched to the incident. A decision is also made as to the dissemination of information about the incident to the motoring public.
Motorist information informs drivers not at the site about the location and severity of the incident so as to enable drivers to better anticipate conditions at the site and give them the opportunity to divert and avoid the site altogether.
Site management refers to the management of resources to remove the incident and reduce the impact on traffic flow. This stage involves three major tasks: traffic management, investigation, and clearance.
- Traffic management is the control of and safe movement of traffic through the incident zone.
- Investigation of an incident documents the causes of traffic incidents for legal and insurance purposes.
- Clearance refers to the safe use and timely removal of any wreckage or spilled material from the roadway.
An Incident Management Plan has the following strategic and tactical program elements (Owens, et al., 2010):
- Management Objectives and Performance Measurement;
- Designated Interagency Teams Membership, Roles, and Responsibilities;
- Response and Clearance Policies and Procedures; and
- Responder and Motorist Safety Laws and Equipment.
Incident Response and Clearance Strategies
The Incident Management Plan will designate the responder roles and responsibilities. It will establish an Incident Command System with a unified command across agencies. It will identify who is responsible for bringing which equipment and resources to the incident site. It will establish response and clearance procedures by responding agency and by incident type. It will identify existing state and local laws that apply to incident clearance procedures.
Table 48 presents a menu of possible incident management strategy improvements that an agency may wish to evaluate using the ATDM Analysis procedure. This table is a summary of the FHWA book, Best Practices in Traffic Incident Management (Carson J. L., 2010). The expected effect of each class of strategies on highway capacities and speeds are included in this table as well.
Source: Adapted from: FHWA, Best Practices in Traffic Incident Management, FHWA-HOP-10-050, September 2010.
Work zone management has the objective of safely moving traffic through the working area with as little delay as possible consistent with the safety of the workers, the safety of the traveling public, and the requirements of the work being performed. Transportation management plans (TMPs) are a collection of administrative, procedural, and operational strategies used to manage and mitigate the impacts of a work zone project.
The work zone maintenance of traffic plan (WZ-MOTP) may have three components: A Temporary Traffic Control plan, a Transportation Operations plan, and a Public Information plan. The temporary traffic control plan describes the control strategies, traffic control devices, and project coordination. The transportation operations plan identifies the demand management, corridor management, work zone safety management, and the traffic/incident management and enforcement strategies. The public information plan describes the public awareness and motorist information strategies (Balke, 2009). ATDM strategies can be important components of a TMP (Jeannotte & Chandra, 2005).
The Work Zone Maintenance of Traffic Plan (WZ-MOTP) codifies the agency’s management strategy. The WZ-MOTP has the following elements.
- Construction Approach – staging, sequencing, lane and ramp closure alternatives, alternative work schedules (night, weekend).
- Traffic Control Operations – A mix of dynamic (ATDM) and static measures consisting of speed limit reductions, truck restrictions, signal timing (coordination and phasing), reversible lanes, physical barriers.
- Public Information – A mix of dynamic (ATDM) and static pre-trip and en-route information (e.g., 511, newspapers, meetings, web sites, CCTV over the web), plus on-site information signing such as, static signs, changeable/variable message signs (CMS/VMS), and highway advisory radio (HAR).
- Travel Demand Management (TDM) – employer-based and other incentives (in addition to public information) for use of alternative modes of travel, including park and ride.
- Incident Management and Enforcement – Generally ATDM measures specified in an incident management plan (I-MOTP), such as: traffic management centers, intelligent transportation system (ITS), emergency service patrols, Hazmat teams, and enhanced police enforcement. A particularly aggressive I-MOTP may be put in place for work zones.
The MOTP must consider several alternative construction approaches (including traffic maintenance) and finally recommend the construction approach that best meets the agency’s objectives for the construction project.
Traffic maintenance approaches to be considered in the MOTP include:
- Completely close work area for short time versus partial closure for longer time;
- Nighttime versus daytime lane closures; and
- Off-peak versus peak lane closures.
Traffic Control Operations
The traffic control element of the MOTP plan specifies work zone speed limit reductions, signal timing changes (if needed), reversible lanes (flagging, etc.), and the locations of physical barriers and cones. The traffic control elements may be dynamic, responding in real time to changing conditions, or they may be more static, operating at prespecified times of the day.
Section 6G.02 of the Manual on Uniform Traffic Control Devices (MUTCD) (FHWA, Manual of Uniform Traffic Control Devices, 2009, accessed November 14, 2011. ) defines work zone types according to the duration, and time of day.
- Duration Type A: Long-term stationary is work that occupies a location more than 3 days.
- Duration Type B. Intermediate-term stationary is work that occupies a location more than one daylight period up to 3 days, or nighttime work lasting more than 1 hour.
- Duration Type C. Short-term stationary is daytime work that occupies a location for more than 1 hour within a single daylight period.
- Duration Type D. Short duration is work that occupies a location up to 1 hour.
- Duration Type E. Mobile is work that moves intermittently or continuously.
Work zones are further categorized by the MUTCD (see section 6G.03) according to the location on the facility. Work zones within the traveled way (Location Type E) are further subdivided by facility type.
- Location Type A: Outside the shoulder (Section G6.06);
- Location Type B: On the shoulder with no encroachment (Section G6.07);
- Location Type C: On the shoulder with minor encroachment, (leaving at least a 10-foot lane) (Section G6.08);
- Location Type D: Within the median, (Section G6.09); and
- Location Type E: Within the traveled way of:
- Section 6G.10 – Two Lane Highway;
- Section 6G.11 – Urban Street;
- Section 6G.12 – Multilane Non Access Controlled Highway;
- Section 6G.13 – Intersection; and
- Section 6G.14 – Freeway or Expressway.
Each work zone type has an associated typical application of temporary traffic controls in the MUTCD. These are described in 6H-1 of the MUTCD.
Public Information Element
The public information element is intended to provide the public with pre-trip and en-route information, and preconstruction and during construction information on the work zone so that the public can plan accordingly. The intent is to encourage those who can, to reschedule or reroute their trip to avoid the work zone during periods of peak closures. Public information includes 511 alerts, press interviews, public information meetings, project update web sites, as well as on-site web accessible closed circuit cameras (CCTV), variable message signs (VMS) and highway advisory radio (HAR).
Travel Demand Management Element
The travel demand management (TDM) identifies incentives that will be provided for alternative modes, such as park and ride lots, in coordination with the public information element. The difference between the public information element and the TDM element is that the public information provides neutral information leaving it to the traveler to choose how to respond. The TDM element provides monetary and service incentives to encourage a particular subset of choices.
Incident Management and Enforcement Element
Incident management includes the development of incident management plans for the work zone. These plans describe the coordination with traffic management centers, the employment of ITS (Intelligent Transportation System) devices, deployment of emergency service patrols in the work zone, and enhanced police enforcement. Enforcement may be reinforced with speed limit feedback signs and other devices.
Special Event Management Plans
Special event management deals with moving people and traffic to and from special event locations, such as a sports stadium, concert hall, or an arena. The objective is to get people and traffic onto and off of the site with minimal backups onto the public transportation system and in a reasonable amount of time. Traffic control officers, temporary cones and signs, reversible lanes, and special signal control plans are often part of a special event management plan. (Carson & Bylsma, 2003.)
A special event management plan typically has the following components:
- Before Event Ingress Control;
- During Event Access Control; and
- Post Event Egress Control.
The Special event management plan will deploy a combination of temporary signing, lane controls, signal timing plans, and personnel, to move traffic into the event venue and out of the venue, much like a short-term work zone. The event management plan will have different gradations of deployment depending on the expected attendance at the event.previous | next