Design Techniques

Roadways considered to be "complete" are not of any one size or description. However, for urban arterials, a number of standard design techniques are typically used:

* Speeds are reduced to be more compatible with pedestrians and bicyclists. This is done by a combination of techniques, included among those listed below.
* Lanes are reduced in width (from 12 feet to 11 or even 10 feet).
* The number of lanes may be reduced, often from 4 to 3, which also improves safety for left turns and allows the most prudent driver to set the speed. This treatment is known as a road diet .
* Sidewalks, if missing, are installed.
* Curb cuts (driveways) may be consolidated to reduce walkway interruptions by moving vehicles.
* Raised medians are installed, which improves safety for crossing pedestrians.
* Universal design features are installed, including audible signals, curb ramps, and providing a 4-foot wide clear path of travel on the sidewalk, in accordance with the Americans with Disabilities Act and Public Rights-of-Way Accessibility Guidelines (PROWAG).
* Pedestrian crossings are enhanced with ladder-stye or zebra-style crosswalk markings, signal modifications such as a leading pedestrian interval or countdown timer , and as needed, flashing crosswalks -- lights embedded in the pavement that flash when activated by a crossing pedestrian.
* Street parking is maintained or installed, which helps to discourage speeding.
* Highway interchanges are modified to eliminate high-speed, free right turns. This is done by "squaring up" the interchange to resemble a typical 90-degree, signal-controlled intersection.
* Corner treatments are installed. These may include curb extensions, right-turn slip lanes, or tighter turning radii, all of which slow right turns and provide greater visibility for pedestrians.
* Transit accommodations are improved in a variety of ways.