Simulation results of ICM solutions in Northern Virginia
This study focused on a comprehensive ICM approach as opposed to traditional measures that rely on traffic diversion and alternate route capacity to manage congestion. System impacts were evaluated using a microscopic simulation model (VISSIM) to emulate traffic conditions on the I-95/I-395 corridor with and without ICM. The corridor included six to eight general purpose lanes, two reversible HOV lanes, a primary arterial (US-1), commuter rail services (Virginia Railway Express), Metrorail services (Franconia to Washington, D.C.), bus services, and park-and-ride facilities in Northern Virginia.
The following ICM applications and strategies were included in the evaluation.
- Variable speed limits
- Ramp metering
- Transit signal priority
- Financial incentives (reduction in fees for transit and parking)
- High occupancy toll (HOT)/high occupancy vehicle (HOV) lanes and HOV bypass
- Increased transit and parking capacity.
Researchers adapted a U.S. DOT ICM analysis, modeling, and simulation (AMS) framework to the I-95/I-395 ICM corridor project to evaluate benefit and costs.
Associated with the basic TMC facilities, highway and transit traveler information, and HOT lanes for the pioneer AMS sites were modified to reflect the specific conditions (such as the number of lane miles) on the I-95/I-395 corridor. The cost of deploying the Transit and Parking Capacity (TPC) strategy completely came from increasing the number of parking spaces, since the existing transit system (especially PRTC buses) had adequate capacity. According to the Virginia Department of Transportation (VDOT), the cost of adding 1000 parking spaces to the Stafford commuter parking lot was estimated at $9.7 million; since this capacity expansion was synonymous with the TPC strategy tested during the project (maximum of 1000 extra spaces), its cost was adopted for use in a benefit-to-cost analysis. Similarly, the VSL system deployed as part of the Woodrow Wilson Bridge project (a leased system), which was identical to the VSL strategy proposed in this project had an estimated cost of $1.5 million per year. All costs were adjusted to year 2013 prices using an inflation factor (1.086 ) obtained from the Bureau of Labor Statistics (BLS) and annualized assuming a 10-year life for all components of the ICM deployment (consistent with AMS B-C framework).
The table below excerpted from the source report shows the annualized estimated cost associated with the deployment. The corridor begins at the intersection of US-1 and I-95 in Spotsylvania, Virginia and terminates at the intersection of the 14th Street Bridge and I-395 in Washington, D.C. (approximately 55 miles).
Annual Cost (2013)
|Basic TMC Facilities||
|Variable Speed Limit System||
|Increasing Transit and Parking Capacity||
|Highway Traveler Information||
|Transit Traveler Information||
Identifying and Prototyping Integrated Corridor Management (ICM) Strategies for Application in Virginia
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ICM Corridor (55 miles): $7.45 Million per year