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St. Paul is rethinking its speed limits

West Seventh traffic
MinnPost photo by Bill Lindeke
A new law allows Minnesota cities to set their own speed limits on city streets.

Speed limits seem simple on the surface, but like many details of our transportation system, they get complicated when you dig a little deeper. A few years ago in this column, I described how speed limits have worked in Minnesota. Compared to our neighboring states, the Department of Transportation has long wielded a firm and controlling hand over those rules. This is why, when you travel to cities and towns in Iowa or Wisconsin, you encounter 20 or 25 miles-per-hour streets on a regular basis while you don’t in Minnesota.

But a lot has changed since 2015, and the picture has grown more intriguing. The compromises forged at the end of last year’s legislative session included a new law that allows Minnesota cities to set their own speed limits on city streets.

“During the 2019 session the state of Minnesota passed a state law that allowed municipalities, but not counties and not the state, to change speed limits within some parameters,” explained Kathy Lantry, St. Paul’s director of public works. “[This is only for] city-owned streets, owned and operated by the city. We now have the ability to regulate speeds different from the way we always used to.”

Director Lantry’s distinction about municipalities offers an important caveat. While most streets in St. Paul might appear equal, under the smooth facade they are organized in a complex way, through multiple jurisdictions. On any given trip through town, you could be driving on city-owned, county-owned, or state and federally controlled streets. Each of those roads has a distinct funding source, sets of regulations, and transportation engineers who design and maintain the right-of-way.


The recent rule change, for the first time in generations, allows cities to have more local control over speed limits. In both Minneapolis and St. Paul, the next step is one where cities, on their streets anyway, can begin to set their own pace, and use street regulations to accomplish civic goals. That’s a big reason for the note of caution on the part of Lantry and cities, who remain a bit cautious about carelessly wielding their newfound power.

“We want to make sure that what are doing with speed limits is defensible and replicable,” explained Lantry. “We want to have good engineering principles behind our recommendations for speed limits.”

The perversity of the 85th percentile rule

The best practices for speed limits date back over half a century to something called the Solomon Curve. It’s a principle named for Douglas Solomon, who did a study for the Bureau of Public Roads in the late 1950s of crashes on rural highways.

Solomon’s report showed that most crashes stemmed from speed differential, that when drivers traveled at greatly different rates, it is much harder to predict and judge behavior. This difference in speeds was a primary cause of crashes. And critically, the data in Solomon’s research posited that it was people driving too slowly, rather than too fast, who were more likely to be the root of problem.

Solomon Curve
US Bureau of Public Roads, 1964
As a result, the practice for transportation engineers for over half a century has been to set speed limits at a critical point that balances the risks of speed differential. And thanks to the curve, that point has been the speed where 85% of the people are driving under the limit.

“The 85% speed is the starting point that MnDOT uses to establish speed limits,” explained Brad Estochen, a traffic engineer for Ramsey County Public works. “We go out and measure free flow on the roadway and figure out what the 85th percent speed is, and that’s the starting point to figure out what speed limit should be established.”

With the 85th percentile rule, setting speed limits too low will create more divergence between the slower (law-abiding) drivers and the average drivers. And because speed divergence creates unpredictability, that’s dangerous.


“MnDOT has their process,” said Estochen. “They’re the ones empowered by the state to establish speed limits. We collaborate, and give input to MnDOT on their process.”

Speed limits in an urban context

Especially in cities, the 85th percentile rule can work in perverse ways. At its extremes, the principle rewards drivers who speed by changing the rules. If enough people break the law, the rule simply changes the law to accommodate them. For decades, that’s been how speed limits were set throughout the state.

That’s the rule that explains what happened on St. Paul’s city-owned Shepard Road.

“What used to happen? Shepard Road, after that was constructed, west of Chestnut Street was originally signed for 40 miles per hour,” explained Lantry. “The city went to the state, per the current state law before this change, and said we want to lower speed limits. But you’re required to do a speed study. What came back was that the state said you have to raise [the limit]. That’s the system that we had, prior to the state law change.”

If you know where to look, examples of the 85th speed rule are all around the streets of St. Paul and Minneapolis. There are lots of places where the speed limits have actually been increased because of the frequency of people speeding.

For example, on St. Paul’s Marshall Avenue, a county-owned road, the speed limit suddenly increases from 30 to 35 miles per hour just east of Lexington Parkway, right in the middle of the historic Rondo neighborhood. In an email, a Ramsey County engineer, Joe Lux, admitted the case was “curious,” and should have been corrected by now.

Marshall Avenue
MinnPost photo by Bill Lindeke
On St. Paul’s Marshall Avenue, the speed limit suddenly increases from 30 to 35 miles per hour just east of Lexington Parkway.
Another example sits on West 7th Street, a state-owned main road running through St. Paul. Just west of Randolph Avenue, the speed limits jump from 30 to 35 miles per hour, despite the street remaining the same width, and being lined with homes and businesses.


Two years ago, because of speeding on West 7th, the city got permission to install temporary bump-outs at the corners of Victoria Street and Otto Street, in the hopes that people could safely cross the street. But while the plastic bump-outs send one message, the speed limit signs continue to send to drivers the opposite signal.

Speeding and crash survival

Those tensions are why transportation officials in Minnesota cities are so excited about having more control over speed limits. Instead of going through the state Department of Transportation for approval of any changes, both Minneapolis and St. Paul are currently floating ordinances to give their own city engineers the power to set the rules.

“There is good empirical data that shows, in crashes between vehicles and pedestrians and vehicles and bicyclists, [reducing speed] saves lives,” explained Lantry. “This is one of those things where there’s no dispute. If a car hits a human being at X miles per hour, what is their likelihood to survive? We know those things. And so our basic entire message is three words: Slower is safer.”

Speed is especially lethal for vulnerable users like pedestrians and people biking. The risk of injury and death increases as speed increases.
Seattle Department of Transportation
Speed is especially lethal for vulnerable users like pedestrians and people biking. The risk of injury and death increases as speed increases.
For people worried about pedestrian fatalities, the new law comes just in time. After years of progress on street safety, the last few years have seen troubling increases in pedestrian fatalities. Reducing speeds, especially in urban areas, is one of the few easy solutions to the crisis.

In St. Paul, there’s no clear direction on where and how low to set the new urban limits. The city engineers are looking at a process to think about where and how low the limits should go, and even weighing a collaboratory approach with neighboring Minneapolis to create consistency between cities. In both Minneapolis and St. Paul, the new ordinances codify the ability of city engineers to set limits. But because of the complexity of roadway jurisdiction, it won’t be a simple matter to make changes.

At their recent budget hearing, St. Paul allocated enough money for 1,000 new speed signs in next year’s public works’ budget. At $325 per sign, that’s a lot of money for new infrastructure, but compared to just about any other investment, they hope this one will have sweeping safety benefits.

“The logistics of changing the speed limit, the concept is easy implementation and operations of it more difficult,” admitted Lantry. “I don’t have staff time to put up 1,000 signs in a week. It’s going to take us some time going to make an implementation schedule.”

Because the state law change does not include counties, the potential reach of the new speed limit freedom is limited to city-owned streets. This is a problem because the majority of fatal and injurious crashes occur not on the residential city streets, but on county- or state-owned arterials. For those streets, the old status quo of high-speeds and the 85th percent rule will still hold sway.

Lacking the freedom given to cities, the counties will still have to make a proposal to MnDOT engineers every time they make a change to the road. That doesn’t mean that there’s nothing they can do about speeding, but it does mean that speed limits cannot be the main answer. Instead, engineering changes will have to be the main factor determining driver safety.

“We’re doing things with roundabouts,” said Brad Estochen at Ramsey County. “We’re looking at roadways, using space a little more wisely to promote safety. Four lanes to three lanes, thinking operationally to pursue those as much as we can.”

The public hearings in Minneapolis and St. Paul on their newfound new speed limit power will be held in the coming months. For St. Paul, it’s this afternoon, Oct. 16; in Minneapolis, it’ll be later this winter. After that, if the ordinances pass, for the first time in decades it’ll be up to cities to set their own speed limits.

“This is as much about getting people to comply as it is culture change,” said Lantry. “The more we can get people used to the idea that speed limits are going to go down, the better.”

Look for lots of new signs, and a public campaign to persuade drivers to slow down on the city streets. If it works, it’ll surely save lives.

Comments (23)

  1. Submitted by Adam Miller on 10/16/2019 - 10:50 am.

    Make the streets (and lanes) wider, with wider shoulders, “curb reaction space” and turn radii for “safety.” Watch people drive faster because of it. Raise the speed limit. Rinse, repeat.

    We’ve got to break each part of that cycle.

  2. Submitted by Frank Phelan on 10/16/2019 - 12:25 pm.

    Wait. The 85% rule comes from a study older than me?

    Ah, we need beter data than that.

  3. Submitted by lisa miller on 10/16/2019 - 12:59 pm.

    No doubt clearly marked turn lanes and such are important. But don’t you think if it was mostly an education issue, it would have happened by now? Enforcement is also key as well as speed bumps. Round abouts in busy areas confuse too many. Look at the areas of the twin cities who have traffic enforcement and then look at crashes. Minnesota drivers are terrible.

  4. Submitted by Alan Nilsson on 10/16/2019 - 02:52 pm.

    Effects of city-wide 20 mph (30km/hour) speed limits on road injuries in Bristol, UK:
    https://injuryprevention.bmj.com/content/early/2019/07/25/injuryprev-2019-043305

  5. Submitted by Ray Schoch on 10/16/2019 - 04:42 pm.

    Disputes over speed limits are as old as cities and any form of transportation faster than walking. I can’t speak for Minneapolis, particularly, but in the 1890s, people complained loudly and often about the reckless behavior of bicyclists. Now – speaking purely as a daily pedestrian – I’m inclined to do the same thing. Pedestrians blame cyclists, who blame oblivious drivers, who blame equally oblivious cyclists and clueless pedestrians.

    Questions worth asking include – but are not limited to – “Who are the streets for?” “Who is responsible for pedestrian / cyclist / driver safety?” “Does everyone have an inherent right to use each and every street?” “How fast is too fast?” “How slow is too slow?” and many others. For a fairly rational discussion of these and other issues that go back to the turn of the last century (i.e., the early 1900s, when automobiles began to be common in American cities) I highly recommend:

    Fighting Traffic: The Dawn of the Motor Age in the American City
    by Peter D. Norton

    If nothing else, Norton’s book will show that there truly are no new arguments in this ongoing dispute between / among drivers, cyclists, pedestrians, municipal and law enforcement agencies, insurance companies, and other groups like the AAA. Public sentiment has swung back and forth between / among the affected groups for pretty much the entirety of the past century. While speed sometimes is a contributing factor in crashes and fatalities, more often – especially in the current multimedia environment behind the wheel of many modern vehicles – the often more important underlying factor is distraction or, if you prefer, lack of attention to the task of driving.

    • Submitted by Bill Lindeke on 10/16/2019 - 08:43 pm.

      That’s a good book!

    • Submitted by Brian Simon on 10/16/2019 - 10:12 pm.

      While I agree with your conclusion regarding distracted driving as an issue that requires urgent attention, your other examples actually fit with the premise of the Soloman Curve. When pedestrians & cyclists share space, the dangers are due to speed differential. Same for bikes & cars. When there’s enough space that different speed groups have designated spaces, things work pretty well. But put a walker or runner on a bike path & conflicts occur.

  6. Submitted by Kayla Landru on 10/16/2019 - 05:33 pm.

    Getting our roads fixed and maintained would make a big difference. Drivers are constantly dodging pot holes. This diversion can easily distract to the degree that accidents occur. Residents who pay property taxes are constantly wondering why are our residential streets are so neglected

    • Submitted by Bill Lindeke on 10/16/2019 - 08:43 pm.

      That, and cell phones. I’d reckon each cell phone causes 10X the distraction as each pothole.

      • Submitted by joseph olson on 10/20/2019 - 01:17 pm.

        BINGO on cell phones. There is distracted walking and distracted cycling too. It is there but hard to measure after an accident.

    • Submitted by Frank Phelan on 10/16/2019 - 08:46 pm.

      and I wonder why property tax payers pay for streets, instead of drivers.

      • Submitted by Brian Simon on 10/20/2019 - 12:10 pm.

        Both groups pay. Property tax is collected at the county level, plus there may be assessments for local streer maintenance. Gas taxes are collected at the state & federal level. Of course, in both those cases, less is collected than we spend (& less is spent than we need), which is a different topic entirely.

        At the state level, the Pawlenty administration explored the idea of replacing the gas tax with a mileage tax, which never went into effect.

  7. Submitted by Brian Johnson on 10/16/2019 - 10:11 pm.

    I live on the corner of one of the busiest interception on the west side. IMHO speed limits aren’t the problem. I have seen everything from mobs of bicycle riders that don’t even bother to stop for the intersection. Too people walking wherever they want and certainly not paying any more attention than drivers are many times much more buried in their phone then watching for any of the cars.

    I truly wish there was an actual simple solution but I would like to see the statistics of how many people specifically in St Paul cause pedestrian accidents because of speed I bet it’s a pretty low number certainly not enough to inconvenience all the citizens of the city.

    Somebody commented in here that the distraction of cell phones are still a huge issue well if passing a law immediately cures a problem that’s evidence to the contrary.

    come on people lost like this aren’t actually constructive they’re just a lot approved that you’re actually doing something, the city council and the mayor are taking action. Like many things in politics these days it’s all about optics rather than reality

    • Submitted by Bill Lindeke on 10/17/2019 - 09:41 am.

      I’m going to guess Robert Street? It’s a state-owned road and will not change.

      Do you think speed limits can help on residential streets like Isabel?

  8. Submitted by John N. Finn on 10/17/2019 - 09:24 am.

    My residential Winona street is narrow enough that only one lane is open if cars parked on each side. That can slow a bit, but recent repaving (potholes gone) and a nearby improved stop light intersection for traffic off a highway feeds some excessive speeds going through.

    Paraphrased comments I’ve heard from neighbors: “Cars go too fast, they should make the street wider.” “I have to go too slow, they should make the street wider.”

    I hope lower limits can be implemented here. Note that 5mph over or more is customarily expected and allowed. So far all the city can do to respond to crashes or fatalities is to make intersections four way stops.

  9. Submitted by Noreen Tyler on 10/17/2019 - 09:45 am.

    Very few people drive at unsafe speeds. Our instinct is to be safe and to keep others safe. No one wants to have an accident. More rules and expensive signage won’t have tbst much of an impact, but may placate a certain segment of the population. Everyone sharing the roads (pedestrians, drivers, cyclists and now scooters) have to stay aware and use common sense. My biggest concern is hitting a drunk or otherwise oblivious pedestrian wearing dark clothing on a poorly lit street. I would rather see the money spent on better lighting.

  10. Submitted by Pat Terry on 10/17/2019 - 11:09 am.

    I litigated car accidents for many years, digging into the facts of hundreds, if not thousands of cases.

    Speeding was the cause of lots of accidents. But what excess speed really does is increase the severity of accidents. The difference between a 20 mph rear-ender and a 35 mph one is huge, in terms of both vehicle damage and injuries.

    People need to slow down. Cities need to do what they can to make that happen.

  11. Submitted by joseph olson on 10/20/2019 - 01:13 pm.

    Yes, indeed. At 15 mph there is 0.2 fatalities. Wanna try that?
    Got the money to hire 2000 new speed limit enforcers?

    The rule of 85 may have been developed by counting crashes but it has a SOLID psychological base. Most people naturally do the right thing because they are reasonable. I have a sports car that can be driven in excess of 150 mph. But I don’t drive that fast, I drive with the flow of traffic (the old 85%) which is usually very close to the speed limit.

    Imagine trying to force drivers to flow at an UNREASONABLE speed. You are trying to make them act UNREASONABLY. Humans have a strong built-in aversion to doing that. They-won’t-do-it. No law can make them.

    The money and effort would be BETTER SPENT on a campaign to get pedestrians (and cyclists) to wear visible clothing (all blue/grey/black in the dark is invisible at any speed), stop, look, and pay attention at intersections, and get their brains out of their cellphone when walking.

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