Rose Hammond pushed authorities for years to lower the 55 mph speed limit on a two-lane road that passes her assisted living community, a church, two schools and a busy park that hosts numerous youth sports leagues.<\/p>\n
\u201cWhat are you waiting for, somebody to get\u00a0killed<\/a>?\u201d the 85-year-old chided officials in northwest Ohio, complaining that nothing was being done about the motorcycles that race by almost daily.<\/p>\n Amid growing public pressure, Sylvania Township asked county engineers in March to analyze whether Mitchaw Road\u2019s posted\u00a0speed is too high.<\/a>\u00a0The surprising answer: Technically, it\u2019s 5 mph too low.<\/p>\n The reason dates back to studies on rural roads from the 1930s and 1940s that still play an outsized role in the way\u00a0speed limits<\/a> are set across the U.S. \u2014 even in urban areas.<\/p>\n Born from that research was a widely accepted concept known as the 85% rule, which suggests a road\u2019s posted speed should be tied to the 15th-fastest vehicle out of every 100 traveling it in free-flowing traffic, rounded to the nearest 5 mph increment.<\/p>\n But after decades of closely following the rule, some states \u2014 with a nudge from the federal government \u2014 are seeking to modify if not replace it when setting guidelines for how local engineers should decide what speed limit to post.<\/p>\n The concept assumes that a road\u2019s safest speed is the one most vehicles travel \u2014 neither too high nor too low. If drivers think the speed limit should be raised, they can simply step on the gas and \u201cvote with their feet,\u201d as an old brochure from the Institute of Transportation Engineers once put it.<\/p>\n \u201cThe problem with this approach is it creates this feedback loop,\u201d said Jenny O\u2019Connell, director of member programs for the National Association of City Transportation Officials. \u201cPeople speed, and then the speed limits will be ratcheted up to match that speed.\u201d<\/p>\n The association developed an alternative to the 85% rule known as \u201cCity Limits,\u201d which aims to minimize the risk of injuries for all road users by setting the\u00a0speed limit<\/a>\u00a0based on a formula that factors in a street\u2019s activity level and the likelihood of conflicts, such as collisions.<\/p>\n The report points out the 85% rule is based on dated research and that \u201cthese historic roads are a far cry from the vibrant streets and arterials that typify city streets today.\u201d<\/p>\n Amid a recent\u00a0spike in road deaths<\/a>\u00a0across the country, the\u00a0Federal Highway Administration<\/a>\u00a0sent a subtle but important message to states that the 85% rule isn\u2019t actually a rule at all and was carrying too much weight in determining local speed limits. In its first update since 2009 to a manual that establishes national guidelines for traffic signs, the agency clarified that communities should also consider such things as how the road is used, the risk to pedestrians, and the frequency of crashes.<\/p>\n Leah Shahum, who directs the Vision Zero Network, a nonprofit advocating for\u00a0street safety,<\/a>\u00a0said she wishes the manual had gone further in downplaying the 85% rule but acknowledges the change has already impacted the way some states set speed limits. Others, however, are still clinging to the simplicity and familiarity of the longstanding approach, she said.<\/p>\n \u201cThe 85th percentile should not be the Holy Grail<\/a> or the Bible, and yet over and over again it is accepted as that,\u201d Shahum said.<\/p>\n Under its \u201c20 is Plenty\u201d campaign, the Wisconsin capital of Madison has been changing signs across the city this summer, lowering the speed limit from 25 mph to 20 mph on local residential streets.<\/p>\n When Seattle took a similar step in a pilot program seven years ago, not only did it see a noticeable decline in serious injury crashes but also a 7% drop in the 85th percentile speed, according to the Vision Zero Network.<\/p>\n California<\/a>\u00a0embraces the 85% rule even more than most states as its basis for setting speed limits. But legislators have loosened the restrictions on local governments a bit in recent years, allowing them to depart from the guidelines if they can cite a proven safety need.\u00a0Advocates<\/a>\u00a0for pedestrians and bicyclists say the change helps, but is not enough.<\/p>\n \u201cWe still have a long way to go in California in terms of putting value on all road users,\u201d said Kendra Ramsey, executive director of the California Bicycle Coalition. \u201cThere\u2019s still a very heavy mindset that automobiles are the primary method of travel and they should be given priority and reverence.\u201d<\/p>\n But Jay Beeber, executive director for policy at the National Motorists Association, an advocacy organization for drivers, said following the 85% rule is usually the safest way to minimize the variation in speed between drivers who abide by the posted limit and those who far exceed it.<\/p>\n \u201cIt doesn\u2019t really matter what number you put on a sign,\u201d Beeber said. \u201cThe average driver drives the nature of the roadway. It would be patently unfair for a government to build a road to encourage people to drive 45 mph, put a 30 mph speed limit on it, and then ticket everyone for doing what they built the road to do.\u201d<\/p>\n Fears about oil prices prompted Congress in the 1970s to set a 55 mph national maximum speed limit, which it later relaxed to 65 mph before repealing the law in 1995 and handing the authority to states. Since then, speed limits have kept climbing, with North Dakota this summer becoming the ninth state to allow drivers to go 80 mph on some stretches of highway. There\u2019s even a 40-mile segment in Texas between Austin and San Antonio where 85 mph is allowed.<\/p>\n Although high-speed freeways outside major population centers aren\u2019t the focus of most efforts to ease the 85% rule, a 2019 study from the Insurance Institute for Highway Safety \u2014 a research arm funded by auto insurers \u2014 illustrates the risks. Every 5 mph increase to a state\u2019s maximum speed limit increases the chance of fatalities by 8.5% on interstate highways and 2.8% on other roads, the study found.<\/p>\n \u201cMaybe back when you were driving a Model T you had a real feel for how fast you were going, but in modern vehicles you don\u2019t have a sense of what 80 mph is. You\u2019re in a cocoon,\u201d said Chuck Farmer, the institute\u2019s vice president for research, who conducted the study.<\/p>\n If elected officials in Sylvania Township, Ohio, got their way, Mitchaw Road\u2019s posted speed limit would be cut dramatically \u2014 from 55 mph to 40 mph or lower. The county\u2019s finding that the 85% rule actually calls for raising it to 60 mph surprised the town\u2019s leaders, but not the engineers who ran the study.<\/p>\n \u201cIf we don\u2019t make decisions based on data, it\u2019s very difficult to make good decisions,\u201d Lucas County Engineer Mike Pniewski said.<\/p>\n For now, the speed limit will remain as it is. That\u2019s because Ohio law sets maximum speeds for 15 different types of roadways, regardless of what the 85% rule suggests.<\/p>\n And Ohio\u2019s guidelines are evolving. The state now gives more consideration to roadway context and allows cities to reduce speed limits based on the lower standard of the 50th percentile speed when there\u2019s a large presence of pedestrians and bicyclists. Authorities there recently hired a consultant to consider additional modifications based on what other states are doing.<\/p>\n \u201cStates have very slowly started to move away from the 85th percentile as being kind of the gold standard for decision-making,\u201d said Michelle May, who manages Ohio\u2019s highway safety program. \u201cPeople are traveling and living differently than they did 40 years ago, and we want to put safety more at the focus.\u201d<\/p>\n It\u2019s unclear whether any of these changes will ultimately impact the posted speed on Mitchaw Road. After years of futile calls and emails to state, county and township officials, Hammond says she isn\u2019t holding her breath.<\/p>\n \u201cI just get so discouraged,\u201d she said.\n<\/p>\n<\/div>\n Fortune Global Forum<\/strong> returns Oct. 26\u201327, 2025 in Riyadh. CEOs and global leaders will gather for a dynamic, invitation-only event shaping the future of business. Apply for an invitation.<\/a><\/p>\nDrivers set the speed<\/h4>\n
Rethinking the need for speed<\/h4>\n
80 is the new 55<\/h4>\n
A town\u2019s attempt at change<\/h4>\n