Statutory speed limits in Ohio are established in the Ohio Revised Code (ORC) for all roadway types. For speed limit information on a specific route, visit ORC Section 4511.21.

Changes to speed limits may take place. Local authorities may request that the Ohio Department of Transportation (ODOT) approve a revised speed limit based on the findings of a ‘speed zone study.’ The ODOT Traffic Engineering Manual (TEM) lays out the requirements for these speed zone studies.

ODOT must approve speed zones that lower statutory speed limits on all state, federal, interstate, and local roadways, and keep a record of all these approved speed limit revisions. Speed zones to raise speed limits can, in some cases, be accomplished by local municipalities, without ODOT’s approval.

How ODOT sets safe speed zones

ODOT strives to achieve an optimal balance between the safety of road users while still enabling travelers to move with minimal delay to their destinations. It is important that speed limits are considered reasonable by a majority of drivers. Most drivers tend to drive at a speed with which they are comfortable. Sometimes the statutory speed limits don’t cover all of the different conditions that might make them higher (or lower) than desirable for the circumstances. However, when the speed limit is set at a level that most drivers consider reasonable, the speed of vehicles is more uniform, resulting a smoother flow of traffic. When doing speed zone studies, ODOT considers various factors such as:

• the development of the area
• roadway features
• traffic volume
• crashes
• the presence of vulnerable road users
• the speed vehicles are traveling

ODOT’s Speed Zoning Committee

The committee is comprised of ODOT staff, local municipalities, metropolitan planning organizations (MPO), Federal Highway Administration (FHWA), and the County Engineers Association. The group intends to focus on the following goals & objectives:

• Provide updated, clear guidance material on the speed limits established by the ORC.
• Review recent research on setting speed limits.
• Update the speed zoning study process to focus on only the necessary data.
• Consider vulnerable roads users into the current speed zoning processes.
• Provide updated and simplified study templates, along with new training materials.
• Incorporate bike and pedestrian data into the speed limit criteria where appropriate.

Learn more about the speed zoning process and committee on the Speed Zones website.