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8.2.1 ODOT 4R / NEW URBAN DESIGN STANDARDS - EXPRESSWAYS
• Design Speed
The design speed of an expressway is a critical element for determining the appropriate
standard to be applied to a given segment. Expressways are usually high-speed roadways
and should be designed appropriately. Most urban expressways should be designed based
upon a 55 mph design speed or higher. In more restrictive urban environments, a 50 mph
design speed may be more appropriate. A 45 mph design speed may be considered only in
highly constrained areas and retrofit situations. Several factors including planned operating
speeds, amount of access control, use of at-grade intersections, use of grade separations and
topography play major roles in determining the appropriate design speed.
• Pedestrians
Design for and accommodation of pedestrians along expressways is accomplished on a case
by case basis. On those expressways that look and function closer to a freeway, pedestrians
generally are not accommodated adjacent to the roadway. Pedestrian movements are better
accommodated on parallel local roads and streets. In some instances, however, a separate
multi-use path may be constructed along expressways. Where multi-use paths are used they
should be a minimum of 10 feet wide. Where a multi-use path is parallel and adjacent to a
roadway, there should be a 5 foot or greater width separating the path from the edge of
roadway.
On some lower speed expressways, or along expressways in highly urbanized areas,
pedestrians may be accommodated adjacent to the roadway. The preferred method is a
sidewalk and buffer strip. The buffer strip should be at least 8 feet, but may be as low as 4
feet under constrained conditions. Sidewalks separated by a buffer strip should be 6 feet.
Curbside sidewalks should be avoided along expressways. Chapter 11 and the Oregon
Bicycle and Pedestrian Plan provide additional guidance to the design of pedestrian facilities
in these areas.
• Shoulders/Bike Lanes
Expressways must include an adequate shoulder. The shoulder is necessary for emergency
parking, disabled vehicles, and emergency response vehicles. The shoulder also provides
significant safety benefits to motorists and bicyclists, as well as improves traffic flow and
capacity. A minimum 8 foot right side shoulder shall be used for all design speeds where no
roadside barriers are used. This width of shoulder is necessary to help distinguish
expressways as a higher order of roadway facility that should ultimately move towards being
an access controlled facility and provide an area for disabled vehicles and emergencies