“I’m sorry, Officer! He came out of nowhere!“
Every cyclist has, at one time or another, had the feeling of being “invisible” to motorists. Bike Delaware has written about this phenomenon – called “inattentional blindness” – which has been extensively studied by psychologists.
But while we have grown to understand why both cyclists and pedestrians can actually be “invisible” to motorists, another and at least equally important question is why our safety has often been “invisible” to traffic engineers.
Traffic engineers pay very close attention indeed to road safety. In fact, for most traffic engineers, road safety (along with congestion) is their job. And yet, despite this focus on safety at the very center of their profession, historically we don’t see many ped/bike safety projects.
Road safety in Delaware (just as everywhere else) is primarily funded through a federal program called the Highway Safety Improvement Program (HSIP). Here are total levels of safety spending for Delaware roads between 2008 and 2013 and the total spending on pedestrian or cycling safety:
Do you see all those zeros for ped/bike safety?
Over 6 years, Delaware spent on average more than $8 million HSIP dollars each year specifically on road safety improvement projects. That’s great. But none of those projects were primarily focused on reducing pedestrian or cyclist fatalities.
Delaware has invested heavily in motor vehicle occupant safety. Perhaps as a result, motor vehicle occupant fatalities are lower than they have been in decades.
Meanwhile, year after year after year after year after year after year, we have spent zero on projects that are specifically about improving pedestrian or cyclist safety. And, coincidentally or not, while motor vehicle occupant fatalities have fallen, pedestrian fatalities have not. There were 30 pedestrian fatalities in 2012. And 26 in 2013. This is actually higher than pedestrian fatalities were 20 years ago! (1994: 18 fatalities; 1995: 29 fatalities; 1996: 20 fatalities; and 1997: 14 fatalities)
Pedestrian and cyclist fatalities now account for over a quarter of all traffic fatalities in Delaware.
What is going on here? Is this a conspiracy by traffic engineers or automobile manufacturers or AAA to drive nonmotorized users off the roads leaving the roads solely to motorists without any distractions from slow-moving pedestrians and cyclists? By, basically, making the roads so hazardous and deadly that all pedestrians and cyclists will be too frightened to walk or bike?
Actually, no. As much as we would all love this to be an episode of “X-files”, there is no sinister government conspiracy going on. The real culprit is more mundane. It’s called “cluster analysis.”
“Cluster analysis” actually seems like common sense. To both engineers AND civilians. (That should probably be a danger sign.) Imagine you have to decide where to make safety improvements. The obvious choice is to ask where are the crashes? and focus your attention and resources there. Most crashes tend to cluster at intersections and so, for decades, engineers have been working to make safety improvements at those intersections.
We now have a lot less motor vehicle – motor vehicle crashes at intersections than we did a few decades ago.
But (and this is the most important fact of this article), motor vehicle – pedestrian crashes don’t cluster.
Let me repeat that: motor vehicle – pedestrian clashes don’t cluster.
I don’t mean that motor vehicle – pedestrian crashes don’t have a pattern. They do, a very strong one. But that pattern is very different from motor vehicle – motor vehicle crashes. Where the latter cluster at intersections, the former are distributed along a very specific category of roads with names like Kirkwood Highway, Dupont Highway and Concord Pike. Motor vehicle – pedestrian crashes primarily happen in Delaware where pedestrians are trying to cross our multi-lane arterial roads.
Now go back to “cluster” analysis and the $8 million + a year we spend every year specifically to improve road safety. All of those projects are going to improve intersections where crash clusters have been identified. What would the effect of those “improvements” on pedestrian safety be?
The answer is nothing. Because that’s not where pedestrians are being killed and injured.
For any engineer who sees road safety exclusively through the lens of cluster analysis (without looking at any other numbers), it’s like no pedestrians or cyclists are being killed in Delaware! And it can seem quite odd – even perhaps insulting – to point out to that engineer – accustomed to thinking in terms of the utility and importance of cluster analysis – that, notwithstanding their efforts, pedestrian fatalities have actually risen in Delaware. For someone who has spent years of their professional career conscientiously trying to improve road safety (using cluster analysis) it can even seem like a rebuke.
It is a rebuke. Cluster analysis has its place. But it’s utterly useless at reducing the number of pedestrians killed on our roads. And engineers have been so focused on (and distracted by) cluster analysis that they have missed the gorilla of pedestrian fatalities standing right in front of them. Like motorists, they have suffered from their own sort of “inattentional blindness.”
But that may be changing in Delaware. Last April, the News Journal reported that DelDOT had formed a new pedestrian / bicycle safety working group. The working group consists of DelDOT, the Office of Highway Safety and the state police, as well as other government agencies. Bike Delaware is also a member of the working group.
Because of the exclusive focus on nonmotorized safety of the new working group, it quickly moved away from the traditional cluster analysis and has instead been focusing on what could be called “corridor” analysis.
The DelDOT-led working group made the first outside presentation of its work today to improve pedestrian safety on Kirkwood Highway (SR 2) in northern New Castle County to a committee at the Wilmington Area Planning Council. I will describe the working group’s insights and proposals in a follow-up article.
James Wilson, an engineer, is the executive director of Bike Delaware.