Rose Hammond has pushed the authorities for years to lower the speed limit of 55 km / h on a two -lane road that passes its assisted living community, a church, two schools and a busy park that organizes countless youth sports competitions.
“What are you waiting for, someone to be killed?” The 85-year-old reprimanded officials in north-western Ohio and complained that nothing was done about the motorcycles that race almost daily.
In the midst of the growing public pressure, Sylvania Township asked in March in the province of therapy to analyze whether the posted speed of MITCHAW Road is too high. The surprising answer: Technically it is 5 km / h too low.
The reason dates from studies on rural roads from the 1930s and 1940s that still play a major role in the way speed limits are placed in the US – even in urban areas.
From that research, a generally accepted concept that is known as the 85% rule, which suggests that a speed posted on the road must be linked to the 15th fastest vehicle of every 100 travels in free running traffic, rounded to the nearest increase of 5 MPH.
But after decades of the rule closely, some states – with a push from the federal government – try to change whether it is not set when setting guidelines for how local engineers should decide which speed limit to post.
Drivers set the speed
The concept assumes that the safest speed of a road is most vehicles that travel – neither too high nor too low. If drivers think that the speed limit should be increased, they can easily step on the gas and 'vote with their feet', as an old brochure of the Institute of Transportation Engineers ever.
“The problem with this approach is that it creates this feedback loop,” says Jenny O'Connell, director of membership programs for the National Association of City Transportation officials. “Accelerate people, and then the speed limits are recorded to match that speed.”
The association has developed an alternative for the 85% rule that is known as 'city borders', which aims to minimize the risk of injuries for all road users by determining the speed limit on the basis of a formula that in the activity level of a street and the probability of conflicts, such as collisions.
The report points out that the rule of 85% is based on dated research and that “these historic roads are far removed from the lively streets and arterials that typify city streets today.”
In the midst of a recent peak in weighing throughout the country, the Federal Highway administration sent a subtle but important message to states that the 85% rule is not a rule at all and has too much weight when determining the local speed limits. In the first update since 2009 to a manual that establishes national guidelines for traffic signs, the agency clarified that communities should also consider how the road is used, the risk for pedestrians and the frequency of crashes.
Leah Shahum, who leads the Vision Zero Network, a non -profit organization for street safety, said that she wishes the manual to continue in trivializing the 85% rule, but acknowledges that the change has already had influence on the way some states have established speed limits. However, others still hold on to the simplicity and fame of the long -standing approach, she said.
“The 85th percentile should not be the holy grail or the Bible, and yet it is accepted that way,” said Shahum.
Reconsideration of the need for speed
Under his campaign “20 is Plenty”, the capital of Wisconsin of Madison has changed signs this summer in the city, reducing the speed limit from 25 MPH to 20 MPH in local residential streets.
When Seattle took a similar step in a pilot program seven years ago, it not only saw a noticeable decline of serious injury accidents, but also a fall of 7% in the 85th percenty speed, according to the Vision Zero network.
California embraces the rule of 85% even more than most states as the basis for determining speed limits. But the laws have loosened the restrictions on local authorities in recent years, so that they can deviate from the guidelines if they can quote a proven safety need. Proponents of pedestrians and cyclists say that the change helps but is not enough.
“We still have a long way to go in California in terms of value to all road users,” said Kendra Ramsey, executive director of the California Bicycle Coalition. “There is still a very heavy mindset that cars are the primary travel method and they must be priority and respect.”
But Jay Beeber, executive director of policy at the National Motorists Association, a representation of interests for administrators, said that following the 85% rule is usually the safest way to minimize the variation in speed between drivers who adhere to the posted limit and those who exceed it.
“It doesn't really matter which number you put on a plate,” said Beeber. “The average driver drives the nature of the roadway. It would clearly be unfair for a government to build a road to encourage people to control 45 km / h, put a speed limit of 30 km / h on it and then to have everyone on a ticket for which they have built the road.”
80 is the new 55
The fear of oil prices led the congress to establish a national maximum speed limit of 55 MPH in the 1970s, which later relaxed up to 65 km / h before the law was withdrawn in 1995 and handed the authority to states. Since then, speed limits have continued to climb, where Noord -Dakota will be the ninth state this summer to let drivers go 80 km / h on some highway pieces. There is even a 40 miles segment in Texas between Austin and San Antonio where 85 km / h is allowed.
Although fast motorways outside the large population centers are not the focus of most efforts to illuminate the 85% rule, a study by the insurance institute for highway safety and a research arm financed by car insurers-de risks. Every 5 MPH increase to the maximum speed limit of a state increases the chance of fatalities by 8.5% on motorways between states and 2.8% on other roads, according to the study.
“Maybe back when you drove a model, you had a real feeling for how fast you went, but in modern vehicles you have no idea of what 80 km / h is. You are in a cocoon,” said Chuck Farmer, vice -president of the Institute for Research, which conducted the study.
The attempt of a city to change
If chosen officials in Sylvania Township, Ohio, would get their way, the posted speed limit of MITCHAW Road would be dramatically cut – from 55 mph to 40 km / h or lower. The finding of the province that the 85% rule actually calls to collect it up to 60 km / h, surprised the leaders of the city, but not the engineers who conducted the study.
“If we don't make decisions based on data, it is very difficult to make good decisions,” said Lucas County Engineer Mike Pniewski.
For now, the speed limit remains as it is. That is because OHIO LAW sets maximum speeds for 15 different types of roads, regardless of what the 85% rule suggests.
And evolve the guidelines of Ohio. The State now gives more consideration to the lane context and enables cities to lower speed limits based on the lower standard of the 50th percenty speed when there is a large presence of pedestrians and cyclists. Authorities there recently hired a consultant to consider additional changes based on what other states are doing.
“States started very slowly to leave the 85th percentile as a kind of gold standard for decision -making,” said Michelle May, who manages Ohio's safety program. “People travel and live differently than 40 years ago, and we want to focus more on safety.”
It is unclear whether one of these changes will ultimately influence the posted speed on Mitchw Road. After years of meaningless phone calls and e -mails to state, provincial and township officials, Hammond says that she does not entail her breath.
“I am just so discouraged,” she said.
