Smart Work Zones: Technology Applications to - PowerPoint Presentation

Smart Work Zones: Technology Applications to Improve Work Zone Traffic Safety Rod E. Turochy, Ph.D., P.E. Highway Research CenterSeptember 15, 2016

N 1. Smart Work Zone Applications 2. Overview of ALDOT Research Study on Queue Warning Systems (QWS)3. Summary of QWS Case Studies Smart Work Zones: Technology Applications to Improve Work Zone Traffic Safety

N Smart Work Zone Applications… What are “Smart Work Zone” applications, anyway?

N Smart Work Zone Applications… Involve the deployment of information and/or communications technologies in work zones to improve safety and efficiency Use of “ITS” (intelligent transportation systems) in work zones Saving lives, time, and money through technology

Real-Time Traveler InformationPurpose: provide drivers with current travel condition information prior to and within a work zone, and may also provide this on alternative routes in the corridorGoal: encourage diversion away from the WZ when congestion exists

Queue Warning Systems Used to alert drivers to existing traffic conditions – “real-time” warningReduce the freq. and severity of rear-end crashesAvoid drivers being surprised by stopped or slowing trafficBenefits: Reduces crashes by up to 45%Fewer rear end collisions and severe crashes resulting in injuries/fatalitiesSocietal crash costs savings between $6,600 and $10,000 per night

Variable Speed LimitsPurpose: to harmonize speeds approaching and within the work zone, calming traffic flow, and warning of slowed or stopped traffic aheadUses sensors, PCMSs , and a processing systemCalculates speeds limits to be displayed on PCMS based on measured speed and/or volume data

Variable Speed LimitProvides drivers with a safe speed limit to drive through a work zone and minimize braking as they approach the queue Benefits:Reduction of potential crashes as drivers approach back of queueReduction of congestion and ease traffic through work zone depending on current conditionsReduction in travel time through uniformity in traffic speeds

Dynamic Lane Merge Strategies Purpose: encourage motorists to merge at specific points as they approach a lane closure, depending on current operating conditionsUses sensors and Portable Changeable Message Signs (PCMS) placed in advanced of a lane closureProvides lane use instructions to driversUSE BOTH LANES, TAKE YOUR TURN – MERGE HERE Two strategies:Early Lane Merge Late “Zipper” Lane Merge

Early Lane MergeAdvises drivers to move out of closed lane well before the forced merge pointWorks best when there is a low traffic volume combined w/high average speedsBenefits:Reduction of aggressive driving and unsafe merge maneuvers Provide significant advanced warning to allow drivers adequate distance to mergeGives positive instructions on lane usage Early Merge Schematic

Late Lane Merge (aka Zipper Merge) Drivers are advised to use both lanes up to the merge pointBetter for high traffic volumes, situations where queueing upstream of work zone is expected to occurBenefits:Maximize available storage upstream of work zone to reduce total queue lengthReduces confusion between drivers Clarifies right-of-way at merge point (“alternate merge”) Zipper Merge Schematic

Automated Speed Enforcement Purpose: reduce aggressive speeding in work zonesSystems detect and capture images of speeding vehicles to be used for enforcement purposesBy combining VSLs w/automated enforcement can increase driver compliance w/displayed speed limits

Entering/Exiting Construction Veh. Notification Purpose: warns drivers of slow-moving construction vehicle that may be entering the travel lane OR warn that a vehicle is exiting the travel lane and to not follow it into the work space

N Overview of ALDOT Research Study on Queue Warning Systems

Background Alabama WZ Crashes 2,630 crashes/yr21 fatalities/yr This is an underestimate!Only 26% reportedMost Common OccurrenceEnd-of-Queue (EOQ) Typically severeCountermeasuresQueue detection & warning systems

Queue Warning Sys. Purpose Inform drivers Avoid EOQ crashesTypical components:Sensors CamerasPCMS“Real-time” warning

Research Motivation FHWA Initiative :Application of advanced technologies in WZ FHWA’s “Every Day Counts” program (3rd iteration)Focus on “Smart work zone” applicationsALDOT – FHWA EDC-3 grantPromote use of smart WZ technologies (such as QWS)ALDOT selected for $100k grant to acquire & deploy QWS

Summarize current QWS state-of-the-practice Develop a traffic simulation model to estimate the traffic effectsEvaluate the impact on traffic safety and mobility of QWS deployed in ALDevelop QWS guidelines for ALDOT to use in future deployments Study Objectives

State-of-the-Practice and Literature Review Development of Evaluation and Data Collection Plans Identify Candidate Projects Development of Safety Analysis Plan Study Tasks

Develop safety analysis methodology consistent with state-of-the-practice and HSM Development of Traffic Simulation ModelData Analysis Conclusions and RecommendationsFinal Report Study Tasks Contd.

Thorough review of use and experiences of other states and research findings Analysis of safety and mobility impacts of initial QWS deployment(s)Recommended practice for future ALDOT deployment of QWS Anticipated Results of the Research Study

N Summary of QWS Case Studies

Texas I-35 $2 billion widening effort of I-35 Length of 96 miles ADT: 70,000 – 110,000Trucks: Day 35% & Night >70%Night lane closures 7pm – 7 amTotal nights deployed: 216Total miles of lane closure: 1,290 miles Total number of crashes: 13

Texas I-35 (no extended queues expected) Two-lane facility with lane closure4 iCone Sensors & 1 PCMS ½ mi 1 mi 1 mi 1 mi Not to scale PCMS

Crash Modification Factors 22% CMF EOQ = 0.559 = 44.1 % Crash Reduction Fewer rear end collisions and severe crashes with the system de ployed than at similar lane closures without deployment Saving between $1.4M - $1.8M in societal crash costs Ongoing savings of societal crash costs between $6,000 and $10,000 per night of deployment

Illinois I-70 / I-57 Effingham, IL Rural collector22 month durationI-70 & I-57 overlap for 6 miles ADT: 45,000 & HV: 45%76 miles of deployed equipmentWZ began 10 -12 miles upstream of project limits Project Limits

Project Limits Limits of WZTMS Deployment 10 -12 mi ahead 25 PCMS 25 portable traffic sensors 20 remote video cameras 1 central base station Password-protected website Portable solar-powered trailers

Illinois I-70 / I-57 Overall deployment and operational costs of $1.545 million Special provision called for the vendor to bid a per month unit priceUnit price included maintenance, operation, and relocation costs Initial mobilization and deployment: $1.5 millionTraffic management system operations and maintenance: $1,800 per month (total of 25 months $45,000) Performance Metrics Warning Message Activation Frequency Typically 0-6 activations of prepare to stop (PTS) messages per month Message Activation Duration 0-90 hours total per month 2-254 minutes per occurrence

Illinois I-70 / I-57 PCMS Messages Displayed for Different Traffic Statuses, I-57/I-64 Project, Mount Vernon, Illinois. Source: IDOT

Project Feasibility Scoring Criteria WZs vary widely in terms of traffic mobility and safety impacts Potential candidates:Bridge/deck replacement Full-depth pavement rehabilitation/reclamation Widening

For more information…Many resources exist…FHWA website on Work Zone Management FHWA publication “Work Zone Intelligent Transportation Systems Implementation Guide” Work Zone Safety clearinghouse websiteQuestions? rodturochy@auburn.edu