940.15 Spacing and Clearance for Right-In, Right-Out Driveways

This guideline describes the recommended spacing and corner clearance for driveways along roadways in urban areas that have a non-traversable median and speed limits at or below 45 miles per hour. A non-traversable median restricts left-turn movements into and out of driveways. Adequate spacing between driveways and corner clearance are both important to maintain safety and traffic flow. Spacing between driveways is to be greater on higher speed routes and in rural areas than in urban areas because of higher posted speed limits.

Research and experience in other states indicates that urban routes with non-traversable medians, shorter driveway spacing and corner clearance upstream from an intersection is acceptable for right-in, right-out driveways. This guideline provides for double the number of right-in, right-out driveway access points compared to situations where left turns into and out of driveways are permitted. It also provides for a shorter clearance distance from corners to the last driveway upstream from the corner. For safety reasons, the downstream corner clearance similar to situations where no non-traversable median is present. Do not use this shorter guideline for right-in right-out driveways where a non-traversable median does not exist (e.g., where there is a continuous left-turn lane.) The shorter spacing is also not recommended in rural areas, where higher operating speeds prevail.

Experience has shown that a shorter guideline for right-in, right-out drives is appropriate where there is a physical barrier that prevents left turns (e.g., a non-traversable median). Regulatory restrictions on left turns (e.g., “No Left Turn” signs) and small traffic islands do not prevent left turns.

Driveway Spacing with Offset Drives and where left turns are prohibited

Move direct access to local streets (not arterials and collectors) where possible. Access can be better accomplished on major roadways through techniques such as frontage and backage roads, joint access, cross access and shared driveways. These guidelines only apply where sight distance allows. Do not allow driveways where sight distance is inadequate even if the spacing guideline would allow them.

Table 940.15 Urban Area Minimum Guidelines *

Roadway Classification	Spacing between Right-In, Right-Out Driveways on Roadway with a Restrictive Median	Upstream Corner Clearance for Right-In, Right-Out Driveways on Roadway with a Restrictive Median**
Major, Freeway	No driveways	No driveways
Major, Non-Freeway	220 to 330 ft.	220 to 330 ft.
Minor	110 to 165 ft.	110 to 165 ft.
* The urban guideline may be applied in rural but developed areas that are not urban, for example, cities with populations under 5,000. On collectors in cities with population under 5,000, the recommended spacing is 110 ft. (same as the urban guideline).
** Downstream corner clearance guidelines are similar to the main corner clearance guideline even when a non-traversable median exists.