Work Zone Mobility and Safety Program
Workbook Table of Contents

Appendix D: Discussion of Answers to Exercises

Module 3 - Answers

  1. Examples of conflicts include:
  • Overlap of construction limits,
  • Contradictory temporary signing and pavement marking plans,
  • Contradictory lane shifts, closures, and sidewalks, and
  • Contradictory work zone information provided to public.

Project coordination is required to ensure that all MOT strategies, including temporary lane closures and various traffic switches are coordinated to minimize road user confusion and impacts. Because of the close proximity of the projects C, D, and E to each other, it is crucial to have lane closures between projects well-coordinated and consistent to avoid driver confusion and potential unsafe situations.

  1. Coordination within and across agencies and other stakeholders of all the projects is crucial for the successful development and implementation of a TMP. Some possible ways to achieve this coordination are:
  • A joint stakeholder meeting to coordinate development of individual project TMPs.
  • An impact assessment of the combined impacts of the projects on mobility and safety, using updated traffic data since several of these projects were designed years earlier.
  • Development of an area-wide TMP including all the projects (A through E) and project stakeholders.
  • Clearly defining roles and responsibilities.
  • A working meeting among all project engineers prior to construction initiation.
  • Regular (e.g., weekly) project meetings to discuss upcoming lane closures, traffic shifts, etc.
  • Central public relations personnel for all projects to ensure consistent public message.
  • Quarterly stakeholder meetings with emergency services, utilities, transit, etc., to keep all abreast of upcoming events.

Module 4 - Answers

  1. Traffic control alternatives to consider include:
  • Weekend/off peak lane closures – have less traffic impacts. However, they may extend project duration.
  • Nighttime only lane closures – maintain normal capacity during the day and have less traffic impacts. However, this type of closure is more costly for labor and may extend project duration. There may also be project lighting issues.
  • Continuous 24/7 lane closures, and detour existing southbound I-5 traffic to other routes – faster construction, reduces the need to set up and take down traffic control, safer for workers, and can provide more work space. This option may have the largest impact to traffic.
  • Part-width construction (reduced lane widths to maintain number of lanes) – easier design, detours may not be needed, and less delays. The option may take longer to construct and have possible safety impacts from narrowed lanes.
  1. Selecting a work zone alternative depends on many factors, such as:
  • Ability to meet thresholds described in the state/agency work zone policy guidelines,
  • Ability to maintain access to surrounding streets,
  • Impacts on pedestrian and bicycle facilities,
  • Impacts to transit and other public transportation options,
  • Duration of the project,
  • Utilities affected,
  • Impacts on emergency services (fire, ambulance, police, hospitals),
  • Safety impacts,
  • Total road user cost (e.g., user delay), and
  • Total cost for work zone management strategies (TTC, TO, & PI&O).
  1. No, the following necessary information is not provided
  • Adequate operational data,
  • Information on lane closure restrictions,
  • Traffic and roadway characteristics of the surrounding street network,
  • Land use characteristics,
  • Any major facilities or traffic sources nearby (e.g., hospitals, stadiums),
  • Pedestrian, bicycle, and transit facilities information, and
  • Crash data.

Module 5 - Answers

Bridge Replacement

  1. The primary public relations issue will be the need to get timely information to motorists about the many lane closures that will take place during the project. It is likely that these closures will cause concern and complaints, and information must be made available to make motorists feel more comfortable about the closures. As the bridge connects surrounding jurisdictions, coordination with the DOT personnel from neighboring jurisdictions is also crucial. Also, coordination with commuter organizations, local residents, local businesses, emergency services, police, and nearby Federal Agencies, will be necessary to keep the residents and commuters informed about the upcoming lane closures, other traffic pattern changes, available commuter options (such as transit incentives), available detours, etc.

    Some of the public outreach strategies to be considered include public information meetings (including stakeholder meetings), social marketing (e.g. Twitter), a project website, changeable message signs that provide motorist information on upcoming lane closures and detours, a temporary intelligent transportation system (ITS) to provide real time information on traffic delays, Highway Advisory Radio, and materials targeted toward bicyclists and pedestrians. Since this is an urban area, a regional TMC is likely available to help monitor current traffic conditions and provide traveler information on permanent message boards.
  2. Some of the potential operational issues include:
  • Peak-hour traffic congestion for both regional commuters and local traffic,
  • Key traffic "hot" spots,
  • Needs of a unique stakeholder - U.S Department of Navy – due to its large workforce and dock,
  • Lighting requirements if work is done at night,
  • Access to key institutions - schools, hospitals, etc.,
  • Need for access to evacuation routes,
  • Traffic capacity of the detour routes, and
  • Truck traffic needs (if detoured).

Some of the strategies that could be considered to address the operational issues include: adjustment of allowable lane closure times to accommodate the peak traffic, ridesharing and carpooling incentives to reduce the peak hour traffic, temporary lighting, developing and implementing an incident management plan, making freeway service patrol available, signal/timing or coordination improvements on detour routes, transit service improvements on major lines and/or detour routes, and a designated truck traffic detour route.

Module 6 - Answers

  1. Monitoring TMP performance helps to:
  • Assess whether predicted impacts closely resemble actual field conditions
  • Gauge effectiveness of TMP strategies in managing impacts
  • Document changes and event occurrences during construction
  • Determine TMP revisions
  • Protect against litigation
  • Determine elements to include/correct in future TMPs

Monitoring TMP implementation is important to ensure contractor compliance with all requirements stipulated, to ensure that the work zone is safe and there is minimal interruption of traffic. The DOT needs to monitor for recurring congestion beyond the thresholds set in the contract. The DOT should also do some monitoring to see if the impacts caused by the project meet any thresholds in the Agency's work zone policy. Such thresholds can be in the form of travel time, queue length, or any other performance measures set forth in the policy. Field personnel as well as the use of technology can monitor conditions on the project to identify when impacts are becoming unacceptable. Some technologies can be set to send alerts to key personnel as queues and/or travel time or traffic speeds get closer to the thresholds. If a threshold is being exceeded, then mitigation measures may be needed.

  1. a. The construction could be expedited either by additional lane closures or extension of lane closure hours. Additional lane closures, for example, reducing to one lane in each direction during the off peak period, may not increase traffic congestion. The volume to capacity ratio will be approximately 60-70%. This will require further discussion with the DOT prior to implementation based on the criteria set. Similarly, extension of existing lane closure periods may not increase the congestion during the peak period. Since there is no reverse peak period the contractor can potentially work from 9:30 a.m. to 5:00 a.m. the following day in the southbound direction. Similarly, work could be done from 6:30 p.m. to 3:30 p.m. the following day in the northbound direction as the volume to capacity ratio is less than 70%. In either case, the impacts to traffic need to be re-assessed based on the proposed changes in lane configuration. If unacceptable impacts will be created, additional TMP strategies may be needed to mitigate/reduce these impacts, or the requested changes may need to be disapproved.

    b. The Agency designated personnel should be involved in reviewing and approving these changes to TMP before implementation. This should include the person the Agency designated as the responsible person for this project, as well as whoever performed earlier impacts analysis for the project. The Contractor's responsible person for the project should also be involved in the process, as appropriate.

General - Answers

  1. New York Avenue SWB operational degradation in the a.m. peak hour is primarily a result of a reduced number of lanes; however, additional traffic turning left at Penn Street (detour) also has an impact. New York Avenue NEB also lost one level of service during construction in the p.m. peak hour. The options to consider include:
  • Retime the signals – The signals can be retimed to give more green for the New York Avenue approaches. This will help to reduce delays and improve the level of service.
  • Lane closure restrictions for peak travel – Another strategy to reconsider is restricting the lane closure hours for New York Avenue during the a.m. peak period. Restricting lane closures during the p.m. peak period will help to maintain an existing level of service for that period.
  • Night work and/or weekend work – The New York Avenue Bridge is in an urban area and is heavily used by commuter traffic. Hence, night work and/or weekend work will help in reducing the work zone impacts during the heaviest traffic periods.
  1. The New York Avenue Bridge reconstruction is a significant project in an urban area. In addition, New York Avenue is a major principal arterial and a designated emergency route carrying an average weekday volume of 65,000 vpd. Hence, the TMP should include an incident management element for an effective and efficient response, site management, site clearance, and motorist information. The crash is of a major type and closed lanes for more than 2 hours. In such cases, immediate response is required from emergency responders (numerous emergency responders and numerous non-emergency responders) including all or some of the following:
  • Emergency Contacts (Fire Department, Law Enforcement, EMS, HAZMAT),
  • Environmental Clean-up Crew,
  • Affected Transportation Agencies,
  • Public Information Officer,
  • MOT Coordinator,
  • News media (regional in nature),
  • Towing companies (Roadway Patrol), and
  • Other Support agencies.

Traffic impacts are far reaching and could include implementing alternate routes and notifying the public. Site management involves significant interagency cooperation among high-ranking incident commanders. Public information strategies to consider may include:

  1. Highway Advisory Radio (HAR) advisories,
  2. PCMS messages,
  3. Media advisories, and
  4. Project Website update.

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