Study confirms that a safer street design doesn’t slow emergency vehicles

Before/after comparison images by the Iowa DOT that the study authors used for illustration.

Making a street safer does not increase emergency response times, a recent study published in the peer-reviewed journal Transportation Research Interdisciplinary Perspectives found. It is the first significant study on the topic, according to the journal article.

Specifically, the study looked at the actual change in emergency response times on streets in Cedar Rapids, Iowa, that went through a 4-to-3 lane conversion similar to Seattle's most common style of safe streets redesign. Researchers Nicole Corcoran, Cara J. Hamann, Michelle L. Reyes, Stephanie Jansson, and Joseph E. Cavanaugh looked at actual EMS response time data and conducted a survey of emergency responders to gather their perceptions. They found no difference in emergency response rates from before to after" implementation.

The team analyzed 3,872 emergency responses in Cedar Rapids, Iowa. Note that even though the 42nd Street data shows faster responses after the changes, the study authors caution that the before data on 42nd was less robust, which is why there is such a wide uncertainty range. Chart description from the authors: Emergency response travel rate (min/km) before vs. after road conversion by road segment." Lower is better.

They also surveyed emergency responders to record their perspectives and found that over half of EMS responders thing that [the safety projects] don't affect emergency response times," according to the journal article. The most common issue EMS responders reported was people not properly yielding to an emergency vehicle, which led researchers to suggest that public guidance on how to properly respond to the presence of EMS vehicles on these roadways may be needed."

Hopefully, this study helps put to rest one of the most frustrating and persistent arguments against safe streets projects. Every time I hear someone use emergency vehicles as an excuse for keeping an outdated and dangerous road design, I want to pull out my hair and scream. These arguments can be effective because it's scary to think that assistance in an emergency might be delayed due to a city street project. There are emergencies, such as heart attacks, where every second counts. But the argument is often used as a convenient cover for people who simply don't want the project to happen. It is also buried under many layers of misunderstanding at best and disinformation at worst.

Dangerous streets are NOT more efficient

Four lane streets do not work well in cities. They completely fail every time somebody needs to make a left turn or cross the street. People may think that 4 lanes moves traffic better than 3 because 4 is a bigger number than 3. But throughput advantages of having multiple lanes crumble under real world conditions. For example, when someone wants to turn left, they stop in the middle of the lane to wait for a break in traffic they can gun it through. When they do this, everyone behind them needs to either stop or make a quick lane change to go around them. A single person trying to make a left turn triggers a series of potentially dangerous situations all playing out at the same time. Meanwhile, state law says that people driving must yield to people trying to cross the street, and essentially every street corner is a legal crosswalk whether it is marked or not. Yet compliance with this law on four-lane streets hovers somewhere around 0% (I don't have an actual study handy to back up this figure, so this is my best estimate based on personal experience). 4-lane streets also encourage speeding because speeding drivers can pass people who are driving the actual speed limit. Speed is the biggest factor in the severity of a collision, increasing the odds of death and injury for those inside and outside the speeding vehicle.

Even if you are a monster who doesn't care at all about the safety of your neighbors, four-lane streets are a bad idea because they are unreliable and inefficient. By simply repainting the lines on the street to have one lane in each direction plus a center turn lane, a street can move a comparable number of cars in a dramatically safer manor. Better yet, safer streets also make it easier for more people to walk, bike and take transit instead of adding more cars to the traffic jam.

Dangerous streets can impede emergency vehicles

Let's say you have a street with four lanes, two in each direction, and car traffic is clogging all of them from curb-to-curb. How is an emergency vehicle supposed to get through? There's no space for anyone to move their cars out of the way. The siren can blare all it wants but people aren't going to be able to move until traffic ahead moves and creates some space. But if you have a street with one lane in each direction plus a center turn lane or bus lane or wide bike lane, an emergency vehicle can use the non-travel lane to get around traffic. For example, I've watched ambulances drive down the 2nd Ave bike lane when downtown streets are full of stopped traffic due to backed-up freeway ramps. People on bikes can easily hop up on the sidewalk or squeeze between parked cars to get out of the way if needed. I've also watched a firetruck move through a packed Pike Place. All the people on foot got out of the way quickly and easily, but the handful of confused tourists in rental cars held the firetruck up because they couldn't find a space to pull over. Emergency response drivers are professionals, and they are very good at finding a way through just about any traffic situation. The only streets that actually block emergency vehicles are streets where all the space is occupied by cars.

None of these benefits of modern safe street designs are accidents. Good traffic engineers today take emergency vehicle movement into account when designing streets. It would be malpractice if they didn't. The same cannot necessarily be said for traffic engineers back in the 1950s or whenever it was those four-lane streets were designed. We know a lot more about traffic operations now than we did back then.

Safer streets lead to fewer emergency responses

An ambulance can't be blocked if the traffic injury they are headed to never happened. Likewise, a safer street with fewer collisions is also more reliable for all road users because traffic is less likely to get backed up due to a crash. A recent internal review of Seattle's Vision Zero program found that 80% of pedestrian deaths happened on streets with more than one lane in the same direction. Traffic collisions are a leading cause of death and serious injury, so we can make a sizeable reduction in emergency responses by making our streets safer.

Conclusion

This study is very helpful and affirming, and should help project teams more confidently assure the public that emergency responses won't be slowed. It is reasonable for people to ask about how emergency responses will be impacted by a proposed roadway change because it's really important, and project teams should be ready to provide a clear explanation of how yielding to emergency vehicles would work after a proposed street design change is in place. If nothing else, doing so could help inform the public on what to do since apparently our EMS drivers think people suck at getting out of their way.