D.C. Mun. Regs. tit. 10, r. 10-A411
The District's roadway system consists of 1,153 miles of roadway, 229 vehicular and pedestrian bridges, and approximately 7,700 intersections. Approximately 17 percent of these intersections are signalized, with about one in three signalized intersections located within the downtown area. 411.1
The roadways in the District are categorized by function, ranging from interstates and other freeways, which provide the highest degree of travel mobility, to local streets, which provide the highest level of access to land uses. Map 4.4 shows the existing roadway system based on a functional classification system described in Table 4.4. 411.2
Map 4.4: Roadway System by Functional Classification
Increases in funding for street maintenance since the mid-1990s have allowed the District to continually improve the condition of its roadway pavement. The District continually monitors and rates the condition of its roadways and bridges. 411.4
Table 4.4: Existing Roadway System Functional Classification* 411.5
Road
Traffic congestion on the District's roadway network occurs primarily on the radial principal arterial roadways. Figure 4.3 illustrates traffic volumes on major streets and highways. The flow of traffic is greatly influenced by north-south movements along the I-95 corridor feeding into I-295 and I-395. These highways carry the heaviest daily traffic volumes in the District with an average of approximately 193,000 daily trips on I-395 and 80,000 on I-295. In addition, the limited number of crossings over the Potomac and Anacostia rivers generates higher volumes of traffic at these gateways than their counterparts in the northern portion of the District. 411.6
Examples of heavy volumes from the south include 93,000 daily trips across the Anacostia River on the Pennsylvania Avenue Bridge, 64,000 trips across the Potomac on the Key Bridge, and 100,000 trips across the Theodore Roosevelt Bridge, also over the Potomac. These volumes can be contrasted with volumes coming into the city from the north and northeast, which include 41,000 daily trips on Connecticut Avenue, 18,000 daily trips on Georgia Avenue, 37,000 daily trips on North Capitol Street, and more than 100,000 daily trips on New York Avenue. 411.7
Figure 4.4: Existing District Traffic Volumes, 2003
As the District is a densely developed city with an historic built environment, the city does not foresee making significant investments in road widening to accommodate more autos. Instead, the District will continue to manage existing roadway resources and provide for viable transportation choices throughout the city. Some of the roadway and bridge investments the city is planning to make within the next five to eight years include:
As part of the Comprehensive Plan revision, an analysis of the transportation impacts of anticipated 20-year land use and transportation changes was conducted. The analysis projected a 20 to 25 percent increase in the total number of transit trips by 2025, and about an 11 percent increase in the total number of vehicle trips. Much of the increase is associated with off-peak travel and a "spreading" of the commute period over additional hours of the day. Vehicle congestion will increase on several corridors. The analysis concluded that new transportation demand management measures and transit improvements will be needed, both in the city and in the region, to keep the system functioning adequately. 411.10
Policy T-2.5.1: Creating Multi-Modal Corridors
Transform key District arterials into multi-modal corridors that incorporate and balance a variety of mode choices including bus or streetcar, bicycle, pedestrian and auto. 411.11
Policy T-2.5.2: Managing Roadway Capacity
Manage the capacity of principal arterials within existing limits rather than increasing roadway capacity to meet induced demand for travel by car (See text box on page 32). Increase auto capacity on roadways only if needed to improve the safety of all travelers, improve connectivity of the multimodal transportation network, or improve targeted connections to regional roadways. 411.12
Policy T-2.5.3: Road and Bridge Maintenance
Maintain the road and bridge system to keep it operating safely and efficiently and to maximize its useful life. 411.13
Policy T-2.5.4: Traffic Management
Establish traffic management strategies that separate local traffic from commuter or through-traffic and reduce the intrusion of trucks, commuter traffic, and "cut-through" traffic on residential streets. 411.14
Action T-2.5.A: Maintenance Funds
Provide sufficient funding sources to maintain, and repair the District's system of streets and alleys, including its street lights and traffic control systems, bridges, street trees, and other streetscape improvements. 411.15
Action T-2.5.B: Signal Timing Adjustments
Regularly evaluate the need for adjustments to traffic signal timing to minimize unnecessary automobile idling. 411.16
Action T-2.5.C: Update the Functional Classification System
Update the functional classification of the city's roadways to reflect a multi-modal approach that better integrates pedestrians, bicyclists, and transit vehicles. Ensure that the updated system complies with federal laws and that changes will not reduce available funding. 411.17
The Concept of Induced Demand
Research shows that urban traffic congestion tends to maintain a self-limiting equilibrium: vehicle traffic volumes increase to fill available capacity until congestion limits further growth. Any time a consumer makes a travel decision based on congestion ("Should I run that errand now? No, I'll wait until later when traffic will be lighter") they contribute to this self-limiting equilibrium. Travel that would not occur if roads are congested, but will occur if roads become less congested, is called induced travel demand. Increasing road capacity, or reducing vehicle use by a small group, creates additional road space that is filled with induced demand.
The provisions of Title 10, Part A of the DCMR accessible through this web interface are codification of the District Elements of the Comprehensive Plan for the National Capital. As such, they do not represent the organic provisions adopted by the Council of the District of Columbia. The official version of the District Elements only appears as a hard copy volume of Title 10, Part A published pursuant to section 9 a of the District of Columbia Comprehensive Plan Act of 1994, effective April 10, 1984 (D.C. Law 5-76; D.C. Official Code § 1 -301.66)) . In the event of any inconsistency between the provisions accessible through this site and the provisions contained in the published version of Title 10, Part A, the provisions contained in the published version govern. A copy of the published District Elements is available www.planning.dc.gov.
D.C. Mun. Regs. tit. 10, r. 10-A411