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Work Zone Impacts . Module 5. What is a WZ Impact Assessment ?. WZ Impact Assessment is the process of understanding the safety and mobility impacts of a road construction or maintenance project. Basic Concept . Determine impacts of project? Acceptable? If yes, no problem
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Work Zone Impacts Module 5
What is a WZ Impact Assessment? WZ Impact Assessment is the process of understanding the safety and mobility impacts of a road construction or maintenance project
Basic Concept • Determine impacts of project? • Acceptable? If yes, no problem • Unacceptable? (Significant project) • Can strategy be found to mitigate impacts to acceptable level? • Yes – develop TMP • No – determine best strategy • Advise stakeholders of possible problems
WZ Impacts Considerations • Maximizing Safety • Road Users • Workers • Maximizing mobility and accessibility • Road user costs • Emergency services • Businesses • Constructability • Building projects effectively and efficiently
Benefits of Assessing Impacts Identify and understand all impacts of the project Identify “significant projects” and determine suitable TMP Aid in identifying and evaluating alternative strategies Monitor and manage WZ impacts during construction
Mobility Impacts • Mobility Issues • Delay • Reduced quality of life issues • Significant Projects – agency definition • Reduced Speeds • Queues and complete stoppages • Freight Interference • Travel time reliability – biggest concern • Delayed deliveries • Unanticipated costs • Emergency response
Safety Impacts • Road user exposure to hazards • Will staging create safety hazards greater than existing? • Worker exposure to traffic • Staging allow for positive protection? • Geometrics during phases • Availability of law enforcement • Speed reduction necessary/considered?
Business Impacts • Access • Temporary entrances • Signing • Pavement • Advance notification of phase changes • Keep owners informed • Work Schedules • Christmas shopping season • Weekends
Residential Access Impacts • Keep residents informed as project begins and progresses • Neighborhood association meetings, newsletters, mailings, etc. • Maintain access if possible
Incident Response Impacts • Ensure access to all areas for emergency vehicles • Hospitals nearby? • Trauma centers? • Plan to provide access within work site • Identify alternate routes • Pre-sign for use during incidents?
Transit Impacts • Transit route through project? • Bus stops • Alternate routes available • Include in PR information
Pedestrian Impacts • MUTCD Part 6D: • If project affects the movement of pedestrians, adequate pedestrian access and walkways shall be provided.
Impact Assessment Proactive versus reactive Use early in the TMP Development process to identify and estimate the magnitude of the impacts Assess impacts on regional basis Use assessment to help evaluate various strategies for mitigating impacts Possibly use assessments to justify TCP revisions after award of project
Goal A good impact assessment process should keep agency from being surprised after project is underway – when it is too late to consider strategies to reduce impacts.
Mobility Impact Assessment Tools • Historical knowledge – “Lane closures do not cause backups on this segment of road…” • Various levels of tools for more detailed analysis • Sketch Planning Tools • Travel Demand Models • Traffic Signal Optimization Tools • Macroscopic Simulation Models • Mesoscopic Simulation Models • Microscopic Simulation Models
Transportation Model Approaches macro meso micro
MacroscopicDelay Estimation Tools • Basic Concept • Special-purpose delay estimators for work zones • Examples: QuickZone, DELAYE, QUEWZ-98 • Strengths • Relatively easy-to-use, rapid analysis • Weaknesses • Limited capability beyond modeling simple “pipeline” analyses • High-level analysis macro
MacroscopicRegional Planning Models • Basic Concept • Steady-state liquid flow • Examples: TRANPLAN, EMME/2, TransCAD, others • Strengths • Can handle very large networks (metro areas) • Weaknesses • Not time sensitive • Complex models, relatively expensive to build and maintain macro
Mesoscopic • Basic Concept • Particle Flow • Vehicles are located on roadways but not specific lanes • Examples: DYNASMART-P, DYNAMEQ • Strengths • Can model sub-regional areas in major metropolitan areas • Weaknesses • Not detailed enough for some operational strategies (e.g., complex signal control) • Model complexity is high, data and calibration resources are significant
Microscopic • CORSIM, VISSIM, and others • Model individual vehicle movements • Requires extensive resources to establish and calibrate • Usually reserved for large and complex projects unless existing model can be utilized
Work Zone Analysis Primer • Aid in selection of the correct tool to use in the analysis • Provide guidance to reviewer to ensure appropriate tool was selected for project
Work Zone Modeling and Simulation • Volume IX • Case studies • Aid for analysts
How Should Results of Assessment Be Utilized? • Formulate policies • Identify strategies that will minimize impacts • Identify critical issues to address in development of TMP • Alternate route availability • Effects on businesses and residents
TMP Development Process Identify Early in Process Analyzing Strategies
Impacts Assessment at Project Level • Consider WZ impacts in the assessments that are performed during alternatives evaluations. • Allocate sufficient funds • Address impacts of multiple projects
Work Zone Impacts Assessment During Preliminary Engineering • Compile project /WZ Scope Information for Alternatives • Assess WZ Impacts of Alternatives at a Screening Level • Analyze Potential Impacts (optional) • Identify WZ Management Strategies • Perform Plan/Program Level WZ Impacts Assessment • Compile Planning-Level Work Zone Strategy
Compile project /WZ Scope Information for the Alternatives • The major categories of information that may be needed include the following: • Project Scope • Roadway/Traffic Characteristics • Other Influencing Factors
Identify WZ Management Strategies • Issues To Be Addressed In Identifying WZ Management Strategies: • TTC Strategies • TO and PI Strategies. • Coordination Strategies with Other Projects. • Costs for the Management Strategies
How to Incorporate WZ Impacts Assessments During Design • Compile Preliminary Engineering Materials • Reassess WZ Impacts • Develop/Recommend Final Construction Staging and TMP • Advertise and Award Contract
Work Zone Impacts Assessment During Construction Assess the impact of any proposed changes prior to the start of work Implement the TMP. Actively monitor and manage work zone impacts during construction. Revise the TMP and implement appropriate revisions, if necessary. Document any findings or lessons for use in performance assessments.
Michigan TMP Template http://www.ops.fhwa.dot.gov/wz/resources/final_rule/mdot_tmp_template/mdot_tmp_template.pdf
Review and Discussion • When should the Impacts Assessment take place in the TMP process? • Does your state have a procedure in place to assure impacts are factored in to the project planning and design?