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RELIEVING CONGESTION. Keeping the Nation’s Arteries and Travel Ways Unclogged ~Anyesha Mookherjee Traffic Engineer, URS Corp. The Text Book Definition.
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RELIEVING CONGESTION Keeping the Nation’s Arteries and Travel Ways Unclogged ~Anyesha Mookherjee Traffic Engineer, URS Corp
The Text Book Definition • “Traffic Engineering is that phase of transportation engineering which deals with the planning, geometric design and traffic operations of roads, streets, and highways, their networks, terminals, abutting lands, and relationships with other modes of transportation.” • Traffic Engineering by Roess, Prassas and McShane
What it Actually Means • Provide transportation from point A to point B that is: • Safe • Fast • Comfortable • Convenient • Economical • Environmentally Compatible
Congestion • Congestion results when traffic demand approaches or exceeds the available capacity of the system • Congestion on roadways leads to • Increased frequency of crashes • Increased average trip times • Increased fuel consumption • Increased green house gas emissions
Leading Causes • According to FHWA (Federal Highway Administration), the leading causes of congestion on US roadways are • Bottlenecks • Traffic Incidents • Work Zones • Bad Weather • Poor Signal Timing • Special Events
The Congestion Relief Toolbox • Improve Service on Existing Roadways • Add Capacity • Electronic Toll Collection and Pricing • Better Work Zones • Travel Options • Traveler Information
Improving Service on Existing Roadways • Access Management • Traffic Incident Management • Traffic Signal Timing
Access Management • At urban intersections separate out the critical turning volumes and provide exclusive turn lanes Major street with shared left through movements causes through vehicles to queue behind left turning vehicles Major street with dedicated left turn lanes movements removes left turning vehicles from the paths of through vehicles
Access Management • Channelize heavy/critical turning movements
Traffic Incident Management • Improve response time for first responders to roadway crashes • Provide breakdown lanes • Centralized traffic management centers • Provide real time data about crash via Highway Advisory Radio (HAR)/AM and FM radio/TV/Highway signs
Traffic Incident Management-A Real Time Example Timeline of Events January 13, 2004 - Tuesday2:45 p.m. Tanker truck explodes on I–95, closing interstate in both directions2:46 p.m. Patroller alerts Maryland State Highway Administration (MSHA) of incident2:47 p.m. Patroller begins turning vehicles around at the scene. 2:54 p.m. Electronic message signs changed on I–95 to inform motorists that the interstate near Baltimore is closed. Traffic redirected to alternate routes3:06 p.m. First fire department arrives on the scene 3:45 p.m. The majority of the fire is under control7:00 p.m. Two of the four lanes of southbound I–95 reopen. 11:30 p.m. All lanes of I–895 reopen January 14, 2004 - Wednesday1:30 a.m. Fire crews wash down roadway2:15 a.m. Southbound lanes of I–95 reopen3:35 a.m. Northbound lanes of I–95 reopen Two firefighters work to control the flames on a tractor trailer that was caught in the explosion of the fuel tanker
Traffic Signal Timing • Pre-timed signals vs. actuated signals • Loop detectors • Camera detectors • Optimization of cycle length • Synchro/SIMTraffic • Systemization of signals within corridor • Interconnect signals • Optimize network using Synchro/SIMTraffic • Adaptive traffic control systems • Split Cycle Offset Optimization Technique (SCOOT)
Add Capacity • Construction of additional traffic carrying lanes • Additional freight rail and light rail service • Incorporate pedestrian paths and trails
Capacity Improvement – Woodrow Wilson Bridge Project • The original bridge was opened to traffic in 1961. • Was designed to carry 75,000 vehicles per day in the year 2020 • Currently carries 195,000 vehicles per day and is projected to carry 295,000 vehicles per day by 2020 • Existing six lane configuration inadequate, causes seven hours of congestion and several mile long backups daily • The drawbridge opened 260 times a year
Woodrow Wilson Bridge Project • New span will have • Ten lanes of traffic to carry I-495 traffic • Two lanes for future rail use in the median • 20 feet higher, will only open 65 times a year after completion
Electronic Toll Collection (ETC) and Pricing • ETC is a technological implementation of a pricing concept using RFID transponders mounted in vehicles • It determines whether the cars passing are enrolled in the program • It alerts enforcers for those that are not • It debits electronically the accounts of registered cars without their stopping, or even opening a window
Electronic Toll Collection (ETC) and Pricing • High Occupancy Toll (HOT) lanes: On HOT lanes, low-occupancy vehicles are charged a toll, while High-Occupancy Vehicles (HOVs) are allowed to use the lanes for free or at a discounted toll rate • Variable Pricing: Pricing on toll facilities are varied by time of day with the intention of encouraging some travelers to: • use the roadway during less congested periods • shift to another mode of transportation • change routes
Better Work Zones • Plan ahead • Use available traffic models to predict effect of closing traffic lanes on queues • Restrict lane closures to off peak and weekend hours • Involve the community. Get the word out
Travel Options • Travel Demand Management • Special Events Traffic Management
Travel Demand Management • Evaluate the effect of new development on existing roadway system • Place the onus of mitigating congestion caused by new traffic on developer • Project traffic demand based on land use and plan accordingly • Provide traveler with options: • Tax incentive for transit • Park and ride • Share-a-ride Transportation Demand Land Use Transportation Facilities
Special Events Management • Parades, games, seasonal tourism can place a sudden burden on the roadway system • Easy to plan ahead as event is not of an unexpected nature • Community and police involvement essential • Detour traffic through alternate routes • Establish a system of one-way routes • Establish more parking
Traveler Information • Creation of 511 for traffic, similar to 911 for emergency • Dynamic Message Signs • Real Time Travel Time Information • Web based • Radio based • TV based
Real Time Travel Time Information Screenshot of traffic conditions in area highways on September 18th 2007 at 5:00 PM from www.traffic.com
In a Nutshell… No one strategy can solve the congestion problem
Questions Anyone? • Useful websites: • www.fhwa.dot.gov • www.islandnet.com/~litman • www.wilsonbridge.com • www.chart.state.md.us/ • www.trafficware.com/articles.html • Feel free to contact me at • amookherjee@sha.state.md.us