Sunday, April 15, 2012

Data doesn’t always tell the whole story

by Michelle Stenzel

I saw a question on Twitter posed recently by @stevevance, one of the co-authors of the Chicago sustainable transportation website Grid Chicago. He asked: “Americans always call for safer streets AFTER people get hit. Why don’t we demand safer streets before people are hit?”

My non-Twitter-length reply: Because we’re focused on making decisions based solely on data, and it seems that according to the general zeitgeist, there “must” be data proving that a person has been injured or killed before a street is considered worthy of upgrades. In my opinion, that’s often a flawed belief. Looking at data to make decisions is often rational, but when we’re evaluating our streets, data doesn’t capture all factors that should be considered. 
A woman and her dog wait on eight inches of yellow paint as cabs and SUVs speed by her on a marked pedestrian crosswalk at Clark and Menomonee. (Photo: Bike Walk Lincoln Park)
Injury and fatality data doesn’t reflect factors like: Is crossing this street as a pedestrian a relatively safe and stress-free experience? Does automotive traffic regularly exceed the posted speed limit? How does the speed of the auto traffic affect people walking along or crossing the street? Do drivers follow the law and stop for people in the crosswalks? Does this street have accommodation for a person riding a bicycle? Is riding a bicycle on this street a relatively safe and stress-free experience? Do drivers follow our state’s three-feet passing law when overtaking a person riding a bicycle? How does the speed of auto traffic affect people riding bikes on this street?

For example, you know that we’ve been advocating for improvements on Clark Street between North Avenue and Armitage. That half-mile stretch of street is four wide lanes for moving traffic, and long stretches between stoplights. This encourages drivers to reach speeds far in excess of 30 mph regularly. They often accelerate to even higher speeds in order to “get through” a yellow (or red) light where Lincoln Avenue joins Clark. There are poorly striped, unsignalized crosswalks with no safety islands, and long sections between stoplights to allow pedestrians to cross. There’s no accommodation at all for bicyclists.

So the end result is that this stretch of Clark Street is full of loud, speeding cars. It’s unpleasant to stand near or walk along the street, drive down the street, cross the street, live on the street, or bicycle on the street. No one would stroll along it just for the pleasant experience. Many storefronts along its edge are unleased, and I can only surmise that the noisy, chaotic quality of the street and low volume of pedestrian traffic is likely a factor. It’s a testament to the general vibrancy and liveability of the neighboring Old Town Triangle area of Lincoln Park that in spite of the many negative conditions, this stretch of Clark Street has been the home of the very popular Green City Market, and is also the new home of the recently opened boutique inn Hotel Lincoln.

On paper, is this stretch of Clark Street “safe”? According to the crash data I can find, yes, it probably is considered to be relatively so. On this map of road fatalities nationwide between 2001 and 2009, I zoomed in on Clark Street from North Avenue to Armitage, and see that one pedestrian was killed at Clark and North Avenue in 2004. Even one death is too many, but there are sadly many other streets that have a greater density of icons marking fatalities. 
Crossing six wide lanes with no signal to get home from the park at Clark and Wisconsin. Unleased storefronts are visible in the background. (Photo: Bike Walk Lincoln Park)
But does that mean this portion of Clark Street is not a good candidate for improvements? No, it doesn’t. Lack of collisions doesn’t reflect the time wasted and stress felt by countless people each year playing a dangerous game of Frogger to cross the street on foot. It doesn’t reflect the countless incidences of pounding heart rates in bicyclists caused by an SUV driver passing 18 inches away at 45 mph. It doesn’t reflect the collective fear and anger felt when a speeding taxi driver blows through a red light and nearly hits a family entering the crosswalk. Just because none of the experiences ended in injuries or death – thankfully – doesn’t mean the status quo is fine. We can do better than that.

In the situations described above, no data collector was standing on the side of the street asking the citizens to evaluate their user experience, in order to document it quantitatively. There are things we just can’t prove with existing data, but we know them from observing them, living them, and feeling them in our soul, and sometimes, that’s enough basis to take action.


  1. There are actually many attempts going on in the transportation research community to create means of capturing almost everything that you've suggested using a data-driven analysis. I'm not agreeing or disagreeing with the data approach, but one question I never see asked is: how much does it cost to pave and maintain that extra set of unnecessary lanes? How much would the long-term maintenance bill go down if we started reducing excessive pavement widths down to what's really needed.

    We should continue to advocate for specific changes where we think something really needs to be done, but we should also advocate for a change in how the street design process works, kind of like is suggested in this article:

    1. Thanks for your comments, tomtakt. I've been thinking about the costs of building and maintaining streets, and agree we should always make sure we only have as much as is needed. This crosses my mind a lot when I am once again struck by the sight of the behemoth eight lanes of outer Lake Shore Drive, combined with another two or four lanes of inner Lake Shore Drive along much of it. I guess that all seemed to be a good idea in the 1930s. -- MS