Ohio Study Suggests 55 Mph Limit on Mitchaw Road May Be Too Low

Rose Hammond, an 85-year-old resident of Sylvania Township, Ohio, has long advocated for a lower speed limit on Mitchaw Road, a two-lane road that passes by her assisted living community, a church, two schools, and a busy park. She has repeatedly questioned local officials about the lack of action on the issue, particularly with regard to the frequent speeding motorcycles that pass by [1]. In response to public concern, Sylvania Township recently commissioned county engineers to analyze the road’s posted speed limit. Their surprising conclusion was that the 55 mph limit might actually be 5 mph too low, based on the widely used 85% rule [1].

The 85% rule, developed from studies on rural roads in the 1930s and 1940s, suggests that the posted speed should match the 15th-fastest vehicle out of every 100 traveling the road in free-flowing traffic, rounded to the nearest 5 mph increment. This approach assumes that the safest speed is the one most vehicles naturally travel. However, critics argue this creates a feedback loop, where rising speeds can lead to speed limits being raised to match [1]. Jenny O’Connell of the National Association of City Transportation Officials explained that this system can result in speed limits being “ratcheted up” to accommodate faster drivers [1].

In contrast, the National Association of City Transportation Officials has developed an alternative approach called “City Limits,” which sets speed limits based on a formula that considers the activity level of a street and the likelihood of conflicts, such as collisions. The association argues that the 85% rule is outdated and does not account for the complexity of modern urban streets [1]. The Federal Highway Administration has also begun to shift its stance, issuing an updated manual that clarifies the 85% rule should not be the sole factor in setting speed limits. The new guidelines encourage communities to also consider how roads are used, pedestrian risk, and crash frequency [1].

Leah Shahum of the Vision Zero Network noted that while the federal update is a positive step, it did not go far enough in de-emphasizing the 85% rule. Nonetheless, some states are already adjusting their approach. In Wisconsin, for example, the city of Madison has been lowering speed limits on local residential streets from 25 mph to 20 mph under its “20 is Plenty” campaign. Similarly, Seattle saw a 7% drop in 85th percentile speed and a decline in serious injury crashes after implementing a similar change seven years ago [1].

California, which has historically relied heavily on the 85% rule, has recently granted local governments more flexibility to adjust speed limits based on proven safety needs. Despite this shift, advocates for pedestrians and bicyclists argue that car-centric infrastructure remains a priority. Kendra Ramsey of the California Bicycle Coalition emphasized that more work is needed to value all road users equally [1].

Jay Beeber of the National Motorists Association defended the 85% rule, arguing it helps reduce speed variation among drivers and that setting arbitrary speed limits can lead to unfair enforcement. He emphasized that drivers generally adjust their speed to match the road conditions and that governments should not build roads to encourage certain speeds and then penalize drivers for complying [1].

The national maximum speed limit in the U.S. has increased significantly over time, from 55 mph in the 1970s to 85 mph in parts of Texas. However, a 2019 study from the Insurance Institute for Highway Safety found that every 5 mph increase in a state’s maximum speed limit results in an 8.5% rise in fatalities on interstate highways and 2.8% on other roads. Chuck Farmer, the study’s author, noted that modern vehicles make it harder for drivers to gauge their speed, increasing the risk at higher limits [1].

In Sylvania Township, efforts to lower Mitchaw Road’s speed limit have been complicated by state regulations that set maximum speeds for different types of roadways. While Ohio has begun to evolve its approach by incorporating roadway context and allowing reductions based on pedestrian and cyclist presence, it remains unclear whether these changes will ultimately lead to a new speed limit on Mitchaw Road. For residents like Rose Hammond, who has spent years pushing for change, the lack of progress continues to be disheartening [1].

Source: [1] Today’s speed limits grew out of studies on rural roads from the 1930s and 1940s. Now states are looking to change guidelines (https://fortune.com/2025/08/17/speed-limits-guidelines-states-road-highway-safety-85-percent-rule/)