One Simple Change to Slow Bridge Speeders

Bickerdyke speeders will slow down for this

Speeding down the North side of the Bickerdyke Bridge has been an issue since it opened over seven years ago. It was written about again this year in this Register-Mail article. It seems to be a problem that we can’t solve, and the residents living along the street just after the bridge are begging for relief. The Traffic Advisory Committee has looked at solutions but hasn’t been able to come up with anything they believe would be a good fit. I think there is one extremely simple, cheap solution that could slow traffic down with almost no drawbacks. But first, let’s talk about street design and what’s setting up drivers to drive fast down this bridge. 

Street Design and Speed

How do you know how fast you are supposed to drive on a section of road? 

Seems like a fairly obvious answer. We are told from the beginning of our driving careers that we always need to be watching out for speed limit signs and to adjust our speed accordingly. We have to be alert while driving because the speed limit can change at any time without much notice and we need to be prepared. If a cop pulls you over for speeding and you say you didn’t know what the speed limit is then you’re screwed if you just passed a speed limit sign.

And for good reason, speeding is actually way more dangerous than we as a society generally understand. Or maybe we do understand but we don’t always demonstrate it in our actions. Even just 10 miles per hour can mean the difference between a pedestrian living or dying in a collision. 

There’s a secret we don’t like to admit to ourselves, and that is that driving is a subconscious activity. If you’ve ever been driving and suddenly find yourself driving to work instead of the store like you planned, you were driving subconsciously. That’s more on the extreme end of subconscious driving but it’s all streamlined in our brains. If the activity of driving wasn’t kicked to the subconscious then we would all be massively stressed about driving any amount at any speed, but we aren’t. 

A part of subconscious driving is that you take clues from your surroundings. This can be lines painted on the pavement, what you see on the sides of the roads, how close the sides of the road are to you, traffic signals, how bumpy or smooth the road is; lots of clues your body subconsciously takes in to determine how safe you feel. Generally the safer a driver feels while driving the higher speed they are willing to go.

This can be seen when you drive through really small towns in the country. You’re driving along in a 55 mph zone, and then all of a sudden it’s 40 mph, then 30 mph, but the road never changes so it feels like a pain to slow down all the way. Those roads don’t give you any subconscious information to tell you to slow down. So what is a road you wouldn’t drive fast on no matter what?

Take for example driving down Osage Street in town.

For those of you that don’t know about Osage Street, it’s a glorified alley that spans two blocks and is quite narrow. Where it ends up connecting on Broad St. is covered by trees and the trees themselves are quite close to the road. It’s also only 17-18 feet wide giving only 8.5-9 feet lanes for two way traffic. Would you drive on Osage as fast as you would on I-74, with it’s wide lanes, median, shoulders, clear area on either side of the road, and smooth top? Even if Osage was longer than two blocks the answer would still be no. Osage’s features tell the driver how fast to drive on it.

The logic normally goes that if you want drivers to drive fast, like on an interstate or highway, you widen the clear area and remove as many possible hindrances. If you want people to drive slower, you give them a narrower spaces to drive in with little obstacles to avoid, nothing too dangerous but enough to keep them thinking and feel a bit of danger if they don’t pay close attention.

Our Bridge

This is where the Bickerdyke bridge runs into issues. The way the bridge currently stands is that at the top of the bridge the road is 28 feet wide, but then at the bottom of the North side it widens out considerably to 38 feet. This gives drivers the subconscious feeling that it is safe for them to drive faster. We can post flashing signs and have cops sitting by at all times to bust speeders, but if the features of the street induce drivers to speed up they are going to speed.

So why was it designed like this? It’s width can be because of two perfectly legitimate reasons. First, the width matches the width of the road it connects to, Seminary St. It seems like good design to have your bridge end up as the same width as the road it’s connecting. Secondly, Cottage Hospital is just a couple blocks away, so if vehicles are blocking the normal lanes then the ambulances have room in the middle to get by. Seconds do matter in an emergency.

So what do we do?

There are many complicated, ineffective, or expensive ways we could use to fix this. We could put up more signs, but that’s already not working. We could install speed humps at the end of the bridge, but that seems like too much of a hinderance for the Traffic committee. We could do a massive project to make the end of the bridge narrower and plant trees, helping produce slower speeds in 20 years. All of those aren’t great, so what can we do today without spending too much money?

One Painted Line

I propose that we paint another line along the right side of the northbound lane, starting somewhere after the top of the bridge that would slowly inch in on the lane. Right now the lane is 13 ft wide when it connects to Seminary, giving drivers subconscious clues to drive faster. What if the line narrowed in to create a 9 ft wide lane against the center lane? It’s much smaller but still plenty big for all vehicles to pass through, especially because the sides of the lane are only paint. With this we aren’t creating any real structures that get in the way of driving, only a perceived narrowing of the road that tells drivers to slow down. We already do it just South on Kelloggs but to a lesser extent.

The proposed line would look something like this:

If we really wanted to lock things down we could install two plastic lane dividers, one on either side of the median, at the bottom of the slope. It would further add to the narrowing effect without creating true barriers. They’re the things that look like this:

All told with materials and labor this would maybe cost between $200 and $500, but I suspect the city already has paint and lane dividers on hand that they could use. It’s a very simple solution, and since it’s such a small change it can be easily reversed if it doesn’t work out. In my not-professionally-informed opinion I’d suspect the number of speeders would go down substantially and the average speed would be lower. This would all come while not changing the actual physical road, but by using some paint and plastic poles to trick driver’s minds into slowing down a little bit. It doesn’t put any extra stress on cars, and it doesn’t hinder speeding ambulances.

And maybe then, the neighborhood can feel a little safer.