Work Zone - 2.10 Work Zone Monitoring
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2.10 Work Zone Monitoring
Traffic conditions in work zones should be monitored as determined by each region to verify assumptions and projections made during project development. Documentation of the findings and impacts of various techniques used to mitigate impacts will assist in the selection of mobility mitigation measures for future projects.
If monitoring of the work zone indicates that the actual delay times or crash rates have exceeded the anticipated thresholds, adjustments to the TOP need to be considered. When traffic operations, either directly within the project or along adjacent routes within the CIA, are not responding to the measures being implemented, additional changes need to be considered. Changes made to the TTCP or the TOP during any stage of the project may result in reevaluation. The cost and effectiveness of proposed TMP changes should be evaluated based on the mobility policy threshold criteria and all cost modifications should be approved by the Construction Engineer before implementation.
The following items may be used to document project incidents and activities:
- IDRs
- Evaluation reports
- Crash reports
- Traffic measuring devices (loops, tubes, radar, RITIS, etc.)
- Video cameras
- Additional devices or methods
2.10.01 Work Zone Field Reviews
(Updated 12/3/2020)
Effective traffic control requires work zone reviews, during both daytime and nighttime conditions. The frequency of reviews for each project should be determined by the local office. The WZMU should provide at least one review per TSC per construction season, for consistency and alignment. The Work Zone Audit Report (Form 0397) should be used by personnel for work zone reviews.
Recommended adjustments to the TTCP during construction should be referred to the Construction Engineer overseeing the project for consideration. Region/TSC Traffic & Safety personnel should also employ the form for periodic review of the temporary traffic control throughout the duration of the project.
Project staff should be actively engaged with local and state law enforcement agencies, and emergency service providers to assure open communications concerning mobility and TIM.
Crash reports should be obtained as soon as they become available. Work zone crashes should be closely monitored and documented. A crash analysis should be performed to determine if corrective action is needed.
2.10.02 Work Zone Delay
Field measurements of actual travel times and delays should be continuously documented throughout the life of the project to assess mobility in the work zone.
If the field measurements show the anticipated design thresholds are exceeded, the Construction Engineer overseeing the project should consider further mitigation. If delays continue to exceed anticipated threshold levels, a Work Zone Construction Peer Review should also be considered.
Each region is responsible for updating and maintaining the information needed for their projects. The information may be utilized for evaluating project and program level effectiveness.
A. Travel Time Delay
The following report may be used for recording work zone travel time delay before, during and after each stage of construction. Work Zone Travel Time Delay Form (Appendix D). The worksheet includes evaluation of the following work zone delay criterion:
- Throughput
- Delays
- Unit travel times (i.e., minutes per mile traveled, also expressed as an average travel speed over the length of the roadway segment)
- Travel time reliability
- Traffic queues
- Additional travel time delay calculations may be performed using RITIS, Bluetooth, or other tools included in Section 3.03 Mobility Analysis Tools.
2.10.03 Work Zone Crashes
Work zone crashes should be documented and an analysis should be conducted. The data must include:
- Traffic crashes
- Crashes involving workers
- Non-motorized traffic
Lead workers, supervisors and/or contractors should communicate with the emergency
personnel who respond to crashes within a work zone. Staff should consult with the
Region/TSC Traffic & Safety Engineer and the WZCPR Team concerning potential
adjustments to the work zone. This information will be used to improve safety on future
projects.
Adjustments should be documented for future reference to mitigate work zone delays and crashes. Personnel may request and meet with the Region/TSC Traffic & Safety Operations Engineer to discuss the specific crash history for any route, segment or facility during work zone planning.
2.10.04 Work Zone Crashes during Construction
(Updated 12/3/2020)
Monitoring work zone crashes during the project and reviewing potential corrective actions may help reduce or eliminate crashes. The Construction Engineer should assign a staff member to monitor work zone crashes during the project. Crash reviews may also indicate no corrective action is needed. The monitor should establish open communication with law enforcement agencies that patrol the project and request notification of crashes and collect crash report information as soon as it is available.
Project staff should provide project information to towing companies or provide a towing service on the project to keep roadways clear. Towing services should be included in the TTCP design when shoulder width is limited or when no emergency pull-offs exist.
The project staff should work with emergency service, and first responders to develop incident response plans. Incident responders are responsible for the protection of the incident area. Incident response plans should contain provisions to initiate site protection with the goal of reopening the lanes or roadway as safely and quickly as possible.
On-site inspections and constructive input by staff, not specifically assigned to the project, should be encouraged. Those less familiar may observe additional items that benefit the project.
Project staff should notify the Work Zone Unit within 12 hours of a known fatal or potentially fatal (type k) crash within a work zone or queue related to a work zone. The project office should notify the Work Zone Unit within 24 hours of a serious (type A) crash if the crash injures a worker, or damages contractor equipment (ie, PCMS boards, arrow boards, etc..). The Work Zone Unit monitors and reports fatal and serious work zone crashes to determine if crashes can be avoidable in the future. Notification can be made by phone call, e-mail, or text.
Modifications or changes to the work zone based on field feedback should be shared with the design staff. This allows the items to be addressed in future work zone designs.
When issues occur that cannot be corrected at the project level, assistance can be requested from the WZMU or a Work Zone Construction Peer Review as detailed in Section 1.02.05.B.
2.10.05 Program Performance Measures
(Updated 12/3/2020)
Performance measures are evaluated to ensure successful implementation and continual improvement of MDOT’s Work Zone Safety and Mobility Policy. The construction phase and the post construction season evaluation are the focus of these measures.
The WZMU will share (when available) data collection techniques and best practices utilized throughout MDOT regions to standardize the mobility analyses and post-season assessments process, to ensure efficiency and effectiveness.
2.10.06 Process Review
(Updated 12/3/2020)
On a biennial basis, a process review must also be conducted that includes an overall assessment of the WZSM Policy. This review will be administered by the WZMU and will be provided to the FHWA, Michigan Division, to provide an assessment of policy implementation with respect to Federal WZSM Rule. Suggested improvements to the manual may also be included in the report.
2.10.07 Statewide Project Review
Statewide level measures may include evaluation of how many or what percentage of significant projects meet policy goals. The following items should be considered for program reviews:
- Travel Time Delay: How many projects were able to meet the 10 minutes work zone delay threshold?
- TMP: How many projects were in substantial compliance with TMP requirements?
- Work Zone Compliance: How many projects received satisfactory work zone safety review ratings?
- Work Zone Crashes: How many projects experienced a change in crash patterns (and/or rates) both positive and negative, during the project duration?
Program review results may be used to determine focus areas for the biennial process review and will help evaluate project significance thresholds. Calibrating the customer’s perception of what is tolerable compared to the established threshold may vary by region or area.
2.10.08 Travel Time Delay
(Updated 12/3/2020)
Travel time delay is the most understandable and quantifiable parameter to the motorist and is considered the primary program-level measure for achieving mobility goals.
Tolerable delays within a work zone have been established according to the mobility thresholds as defined in Section 2.01 Project Significance. The success of the WZSM Policy depends directly on how often a motorist actually experiences work zone impacts that are perceived as intolerable.
Actual travel time delays should be periodically measured by field personnel during typical peak traffic periods. A sample field data collection sheet is provided in Appendix D. Software can be used for determining time delays, however those measurements should be verified by field measurements from personnel on the ground.
For high-volume sections, automated devices may also be utilized for data collection, to determine travel times. For more information, refer to Section 3.03 Mobility Analysis Tools.
Travel time measurements serve two primary purposes:
- Monitor and ensure vehicle delays remain at or below predicted delay levels.
- When a project delay exceeds the anticipated work zone delay, the Construction Engineer should be notified and mitigation measures assessed and implemented.
2.10.09 Work Zone Compliance
A work zone survey may be distributed on an annual basis by the WZMU to each region to determine focus areas for the following construction season.
Each region should review ongoing projects and make necessary adjustments during the construction season. For each project review, a standardized report (Form 0397) may be completed that will yield the following determination.
- Was the work zone in substantial compliance with the provisions of the contract documents or agreements during the review?
2.10.10 Statewide Work Zone Crash Evaluation
The WZMU will perform a yearly high level work zone crash analysis. Each Region may compile a summary report of work zone crash data for submittal to the WZMU for analysis. The summary may display the number (or percentage) of projects that showed an increase or decrease in crashes during construction from pre-construction conditions.
Crash data from the period beginning on the start date of the construction project and ending on the completion date of the project, may be compared to crash data from the same period for the previous three years. This detailed review is a best practice and should be considered when the overall volume of crashes increases for the region compared to the previous year.
Assistance may be available from the WZMU if all the required project information (dates and locations) is provided. Noticeable and noteworthy trends detailing when and where crashes have increased will be presented during work zone safety trainings. For more detail, refer to Section 2.04 Work Zone Crash Analysis for more detail).
2.10.11 Customer Feedback and Perception
Customer feedback is essential for assessing whether the current project significance thresholds match what motorist consider tolerable as defined in Section 2.01 Project Significance. The effectiveness of the policy will also be assessed and may be calibrated to what motorists consider tolerable.
2.10.12 Project Review
The provision pertaining to use of work zone data is provided in Section 630.1008(c) of the WZSM Rule. It requires agencies to continually pursue improvement of work zone safety and mobility by analyzing work zone crash and operational data from multiple projects to improve agency processes and procedures.
Work zone data may be used to conduct post-construction evaluations, support process reviews, develop lessons learned, and ultimately improve agency policies and procedures. This data is typically available during project implementation and must be documented for post-construction analyses. It should include project contacts, supporting data, analysis techniques and results, work zone monitoring data, work zone reviews, and other related information. Project-level performance measures are summarized as follows:
- Roadway type
- Total delay field measurements
- Work zone audit reports
- Traffic crashes
- Public Feedback
