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Freeway Management
Congestion costs travelers in wasted time and fuel consumption. The Texas Transportation Institute annually releases its Urban Mobility Report which evaluates the major metropolitan areas across the United States. For the Portland metropolitan area, the annual delay per traveler at peak hours is 38 hours. The cost of congestion for the Portland metropolitan area was $625 million in 2005. Aside from insufficient capacity and physical bottlenecks, the second biggest contributor to non-recurring congestion is incidents (such as crashes and disabled vehicles). Reduced capacity whether due to congestion, incidents, or other events show the need for a well-managed traffic and incident management program.
 
A comprehensive traffic and incident management program looks at addressing multiple facets of the problem from improving detection and response to expediting the delivery of traffic information to allow drivers to make informed travel decisions. ITS operational treatments such as proactive incident response, freeway ramp metering, and coordinated traffic signal operations with arterial streets collectively work together to help mitigate the effects of congestion and to improve traffic flow.
 

Incident Management

Incident Response
 
ODOT’s incident response (IR) crews play a crucial role in Oregon’s Quick Clearance efforts.
Quick Clearance refers to actions that might be taken to minimize the actual clearance of an incident.
 
 
Formerly called COMET (Corridor Management Teams), This program is a freeway service patrol consisting of staff working to clear blocked lanes and to assist with disabled vehicles in Region 1. They patrol heavily used corridors in the Portland-Metro area; however the IR crews can also be dispatched to an incident anywhere within Region 1, covering approximately 890 highway miles. The purpose behind IR is to quickly restore traffic flow to pre-incident levels especially during peak travel hours. Their ability to quickly clear incidents from Oregon's highways benefits the public by reducing delay and reducing fuel consumption. For more information on the benefits of incident response in Region 1, please see the study conducted by Portland State University [2].
 
 
ODOT has implemented a similar program in Region 2. Currently, there are responders that patrol the Salem, Eugene, and coastal areas. They will also respond to incidents in other locations as requested by dispatch. The responders can be dispatched to an incident anywhere within Region 2, covering approximately 1937 highway miles. Overall, this has been a well-received program in the region. The IR crews have established positive working relationships with other first responders such as Oregon State Police and Fire. For an evaluation of Region 2's incident response program, please see Portland State University's research paper [3].
 
Transportation Operations Center (TOC)
 
Oregon has four Transportation Operations Centers that provide mission critical services (traffic surveillance, road/weather condition monitoring, incident detection, etc.) to the public and several Operations, Maintenance and Incident Response programs. The TOCs share a common goal - to provide and track, in the most efficient means, transportation information to disseminate to ODOT operations, Law Enforcement, and other State and public transportation systems for use in their respective service areas. Center operations include many independent software programs (Computer Aided Dispatching, Highway Travel Conditions Reporting System, Variable Message Signs control, Road and Weather Information System, and other centralized and non-centralized programs) to perform a variety of tasks. Currently, a development project, TOCS, is underway to standardize and improve operational efficiency.
 

CCTVs

CCTVs
 
Roadway cameras are an indispensable tool for dispatchers in ODOT's transportation operations centers to assist in managing incidents as well as monitoring traffic and road conditions. These same camera images, viewable on TripCheck, allow travelers to make decisions regarding when, how, and which way to go before heading out on the road. A real-time speed map of the Portland area provides a snapshot of potential slow downs. In general, users of pre-trip travel information resources improve travel time reliability by as much as 5% to 16% [7].
 

Ramp Meters

Ramp Metering
 
Ramp metering, one of the earliest traffic management technologies used by ODOT, was implemented along a segment of I-5 in 1981 [4]. After the ramp meters were installed, the average speed northbound for the PM peak hour increased from approximately 16 mph to 40 mph[5]. In an internal evaluation by ODOT of weekend traffic on US 26, it was revealed that the amount of traffic that could move through the corridor increased on average by 5% due to metering. [6]
 

Other ODOT Projects

Resources and References

  1. Texas Transportation Institute's Urban Mobility Study. 1995.
  2. Bertini, R.L., Rose, M.W., and El-Geneidy, A.M. Using Archived Data to Measure Operational Benefits of ITS Investments: Region 1 Incident Response Program. Portland, OR. June 2004.
  3. Bertini, R.L., Tantiyanugulchai, S., Anderson, E., Lindgren, R. and Leal, M. Evaluation of Region 2 Incident Response Program Using Archived Data by Portland State University. Research Report PSU-CE-TRG-01-01. Portland, OR. June 2001.
  4. Piotrowicz, G., and Robinson, J. Ramp Metering Status in North America 1995 Update. DOT-T-95-17. Washington, D.C. June 1995
  5. Bertini, R.L., Rose, M.W., El-Geneidy, A.M., Eder, A., Leal, M., Malik, S., Tantiyanugulchai, S., and Yin, T.Using Archived Data to Measure Operational Benefits of ITS Investments: Ramp Meters. Portland, OR. June 2004.
  6. Oregon Department of Transportation Region 1 Traffic. Implementation and Operational of Weekend Eastbound US 26 (Sunset Highway) Ramp Metering System. Portland, OR. December 2003. .
  7. US DOT Traveler Information Benefits Database