Pedestrian Safety Guide and Countermeasure Selection System


East Wells Street in downtown Milwaukee was recently converted from a one-way street to a two-way street. Source: Flickr – Dave Reid (2011)




One-way/Two-way Street Conversions

Converting a one-way street to a two-way street is an increasingly popular way to manage traffic patterns, improve access, and change the character of an neighborhood from being a “pass-through” to a ”destination” for motorists. Converting a one-way street to a two-way street can also help reduce motor vehicle speeds and vehicle miles traveled (i.e. less need to circumnavigate multiple streets to reach destinations in dense mixture of land uses) and provide improved conditions and access for bicyclists.

In terms of pedestrian safety, there are benefits of both one-way and two-way streets, so the decision to convert a two-way street to one-way (or vice versa) is context sensitive. Studies have shown that converting two-way streets to one-way generally results in fewer crashes involving pedestrians because there are fewer turning movements. However, one-way streets tend to encourage higher motor vehicle speeds, and intersections involving one-way streets may be more confusing for some roadway users, especially non-local residents and child pedestrians. In addition, left-turning motor vehicle drivers may be less cautious when turning from one-way streets and less inclined to see crossing pedestrians due to poorer sight lines. Two-way streets may reduce vehicle speeds due to increased turning movements and to increased perceived friction along the roadway. In addition, many one-way streets are multi-lane, which creates a multiple threat condition for pedestrians crossing the road. Converting a multi-lane one-way street to a two-lane two-way eliminates this safety issue.

If a street is converted to one-way, it should be evaluated to see if additional changes are should be made. Potential changes include lane diets, road diets, curb extensions, turning radius reductions, and signal timing that discourages high vehicle speeds. Also, traffic circulation in the surrounding area must be carefully considered before converting streets to one-way.


Reduce vehicle speeds and vehicle miles traveled and improve access and economic activity in areas with a dense mixture of land uses such as downtowns and commercial streets.


• Consider impacts on other streets and overall circulation system.
• Be aware that one-way streets may decrease automobile accessibility to businesses.
• Caution is required to minimize potential speeding problems where a two-way street is changed to a one-way street. Redesign or traffic-calming measures may be required to address this.
• Tends to improve signal synchronization on the one-way streets, but hinder synchronization on cross-streets.
• Generally requires a one-way couplet (i.e. if one street is converted, then a nearby street will also likely need to be converted to one-way).

Estimated Cost

Costs for this countermeasure will vary widely depending on the extent of the one-way/two-way conversion.

Case Studies

Allegheny County, PA
Queens, New York