Sunday, December 20th, 2009

The Safety Bogeyman

In order to implement any sort of major capital project that involves the use of federal funds, cities and states have to conduct an Environmental Impact Statement first. One of the things that is done as the first stage of this is to create something called a “Purpose and Need Statement”. Few people really know or care what an EIS is, and even fewer recognize the importance of the Purpose and Need Statement. Any alternatives that are proposed for the project are to be judged by how well they meet the purpose and need of the project. So if your Purpose and Need Statement only talks about, for example, reducing highway congestion, it is an almost sure bet that some sort of highway widening alternative will be proposed. In effect, you can telegraph the solution simply by correctly defining the Purpose and Need, which is why it is so important to make sure that broader community goals, objectives, and aspirations are included in it. They seldom are.

I want to highlight one particular EIS Purpose and Need for illustrative purposes. That is the one for the US 31 corridor in Hamilton County, Indiana. The purpose and need of the project was three fold:

  • Reduce congestion for the US 31 corridor by improving to LOS D or better
  • Improve the level of safety for motorists using the US 31 corridor
  • Provide for the reliable and efficient movement of commerce and regional travel

This is a pretty standard list. It should come as no surprise reading it that the EIS recommended widening and upgrading it to a freeway. If your purpose and need is “driving nails”, it’s no shock when the outcome is “buy a hammer”. Now, I happen to support this project since it is clearly needed. But the narrow scope of the EIS has important consequences. For example, US 31 is a huge barrier dividing the town in two. The project should have had as one of its purposes “Reducing physical barriers between communities”. Because it was not, unsurprisingly many of the things that would have done that were either not included or deemed not cost effective. For example, there are actually no specifics at all around pedestrian or bicycle facilities.

I don’t want to belabor this particular EIS since I already wrote an in depth review of it. Rather, I want to home in on this idea of safety.

Is US 31 dangerous? The EIS notes that “nine of ten segments along US 31 have had overall collision rates higher than the Statewide average rate for similar facilities.” Seems like there might be a problem. But is there?

Keeping in mind Garrison Keillor’s quip about Lake Wobegon being a place where “all the children are above average”, by definition 50% of all roads will have crash rates above the average. This will be true no matter how many road improvements we make. We could reduce crash rates across the board by 90% and half of road segments will still be more dangerous than average.

What this does is build in a bias for road improvements to address safety issues. This particular EIS did not even attempt to compare crash rates against a target level for this type of facility or any other type of metric of what should be expected apart from comparison to the average. For any road with a crash rate above the average (which is by definition half of them), “improving safety” is an all purpose rationale for highway investment. It’s a bogeyman that can be used to scare us into projects.

Of course it almost goes without saying that the only safety measure the EIS authors bother to discuss was that for motorists. The Purpose and Need Statement literally says that the only safety purpose is improving it “for motorists”. I copied those bullets directly from the document.

In fact, I doubt that there were many injuries or deaths among pedestrians or bicyclists. That’s because this 4-6 divided mega-highway is so manifestly unfriendly and unsafe to anyone not in a car, few others would dare to even try to so much as cross it. This condition, naturally, was not viewed as a deficiency in the Purpose and Need Statement. It shows the subtle ways that even generic, seemingly unobjectionable statements bias the outcomes.

Again, I support a healthy investment in highways and even the particular project in question (presuming they get the pedestrian/bicycle parts in during design). I just think we need to take a hard look at how these projects are justified. I’d be surprised if some standards on crash rates didn’t exist. If not, they could easily be created. Possibly they could be benchmarked to averages, with targeted declines over time. To justify a road improvement by using “safety” as a rationale would require a specific level of deviation from the target, not merely an appeal to being less safe than average.

Possibly there are some guidelines to this effect today, but if so, they would appear to be more honored in the breach. This notion that improvements in highways are justified due to merely being below average in safety and not with regards to some objective deficiency should be revisited.

Topics: Public Policy, Transportation

19 Responses to “The Safety Bogeyman”

  1. Alon Levy says:

    According to Smeed’s Law, any safety improvements in infrastructure will just cause people to drive more dangerously, offsetting the safety benefits. Instead of casualties going down, road speed would go up, or the number of cars on the road would go up. A second law due to Smeed is induced demand, which ensures that increasing capacity causes people to drive more, offsetting the congestion reduction.

    So a more honest statement of purpose and need for this project should be, “Increase road capacity on US-31.”

  2. Steve gross says:

    Quick note for you: Technically your math is incorrect. You have confused median with average. While it is true that 50% of any sample will be above the median, there is no requirement that 50% of a sample be above the average. For instance consider a sample of 1,1,1,1,10. The average is 3, but only 20% of the sample is above average.

  3. If I were to sum up three years of legal education, it would be “He who frames the issue wins the debate.” You have provided an excellent real-world example. If I can define the goal(s), I can provide the means.

  4. Gregory Travis says:

    A first-order examination of this would be to try and take an assessment of the future ten or twenty years out. Will tomorrow be just like today, only more so (the central assumption behind the EIS)? Or is it likely to be very different, given the resource challenges (particularly in energy) that we are likely to face as China and other emerging nations demand a bigger piece of a shrinking pie (I know, I know, next year we’ll all be tooling around in our hydrogen-powered electro-mobiles so no worries)?

    A second-order examination might be to review the academic literature and experience regarding such “capacity expansions.” As far as I know, no capacity expansion obtained by road widening has ever achieved even its stated goal of reducing congestion. As a poster above noted, induced demand eats up any capacity increase in, what, an average of just seven years.

    If insanity is defined as doing the same thing over and over again, hoping for different results, than this is crazy.

    Finally, as the same poster above noted, risk homeostasis is a pain in the ass. Initially, again as experience has shown over and over again, the increased capacity will simply be used to underwrite higher travel speeds and more reckless driving — that is until the extra capacity is used by by the increased sub- and ex-urbanization that it enables.

    We can also look to William Langewiesche’s concept of “normal failure” (attempts to increase safety accomplish their goals until a nadir in accidents occurs — past that nadir attempts to increase safety actually make the system less stable and each safety increase attempt results in more, and worse, accidents.

    For example, the ValueJet 592 crash of 1996 where more people were killed by emergency oxygen sensors than had ever been saved by them).

    So yes, it is very true that exactly half of all roads need to be less “safe” than the median road. I suppose we could design the mother of all dangerous roads, something with an accident rate a few orders of magnitude worse than the next worse road and then, on average, most roads would be relatively safe.

    Maybe that’s what the US 31 EIS should seek to do — make the most dangerous road in Indiana so that every other road gets a big boost in its safety rating. That’s taking one for the team.

  5. headly says:

    Maybe you should go to work for the Feds and get the EIS process changed if it doesn’t meet you personal template.

  6. Steve Mouzon says:

    Widening roads cause people to feel safer and therefore drive faster… no real debate there. And collisions at higher speeds are much more likely to cause injury and death than low-speed collisions. So it seems that their design solution might actually have the opposite effect.

  7. DRT says:

    To be clear this is not simply a widening of US 31. They are upgrading it to a limited access freeway, where before it was a highway with traditional stoplight intersections. I don’t think there is any doubt that making it a limited access freeway will make things safer.

  8. Steve Mouzon says:

    Got it… I didn’t understand that. So yes, it’ll be safer, but there are now other implications because they’re turning it into a Cheapway, not a Freeway. A Cheapway is a limited-access thoroughfare through an urban place that destroys more real estate value than its cost of construction. In other words, if you spend a billion dollars building a Cheapway through a city, you’ll destroy over a billion dollars of adjacent real estate value along its path. And the blight that’s created acts as a very effective dam, separating one side of the city from the other. Freeways belong in the country, not the city. Build boulevards and avenues in the city, not Cheapways.

  9. The real issue is safe pedestrian crossings over this wide highway. The EIS simply punted on this point. INDOT has been trying to ram through minimalist solutions (e.g., a sidewalk on one side of a bridge) according to some presentations I saw.

  10. Steve Mouzon says:

    Ever count people crossing a pedestrian footbridge over an interstate? It’s a prescription for a boring day. Problem is, a Cheapway so degrades the urban fabric on both sides to a depth of several blocks that there is usually a very light pedestrian load on the sidewalks either side of the Cheapway that want to go from one side to the other.

  11. John says:

    An EIS isn’t always required with federal funds, just for really big projects that have major impacts. Planners and engineers can often do a smaller version called an Environmental Analysis (EA) instead. Spot on with the analysis though.

  12. Steve,

    I agree it is seldom pleasant to cross a freeway. However, Carmel (one of the two towns this passes through) has really been working hard dramatically improve quality of space. They are rebuilding miles of streets with 8-ft sidepaths on both sides. They also spent a decade battling the state to gain control of a similar road on the other side of town. They are also making it a freeway, but with very tight roundabout interchanges and the freeway depressed under the roundabouts to the extent the water table allows. It is a dramatic improvement in pedestrian and bike experience. In fact, the main purpose of the project is linking the communities on the two sides. You can find out more about:

    Westfield, the other town, has its downtown directly adjacent to US 31, so it isn’t unreasonable to hope that people in housing developments on the other side might want to walk or bike to get there.

  13. Alon Levy says:

    Depressed freeways aren’t much better than at-grade ones – just look at what happened to the South Bronx after Moses rammed the Cross-Bronx Expressway through it.

  14. Yes, but in the Carmel case the freeway is in effect already there. The existing road is a four lane divided highway, limited access, with fenced ROW, etc. All it has are huge signalized intersections with no crosswalks. The upgrade project isn’t expanding the ROW one bit, and dramatically reduces the amount of pavement pedestrians have to cross. I’ve walked through one of the new interchanges. It is night and day.

  15. Travis says:

    I find it interesting that most of these posts have been on the plans that they had set out for the project and very little on what can be done for pedestrian traffic without it seeming like a second thought to vehicles. There is alot of housing close enough to the road and as we all know there is just about everything a hoosier could need or want lining it. I think a good place to start would be some examples of how this problem has been fixed before. Unfortunately I can not name one place i have noticed this to be accomplished. In chicago they just throw in areas for people to stand in between all of the lanes of traffic but that is neither safe nor pleasing. Pedesrian bridges come off as a second thought unless if they have a high amount on context with the site like Frank Ghery’s in millenium park, and how are we suposed to convince people to walk or ride their bike while there are hardly any bike racks and there are giant parking lots around every store and restaurant pedestrians will have to cross. The problem with every solution i can think of is that the area was never designed for pedestrian use in the first place. This means it will be a very slow transition away from vehicle use

  16. AmericanDirt says:

    It would seem that the average/median notion argued here is a moot point for INDOT–possibly interchangeable. I learned about their looseness with terminology a few weeks ago when I inquired about US 31 South, at the interchange with I-465. Previously there had been grade separation at the US 31 bridge to at least have some protection for pedestrians needing to use the highway to cross I-465. Now, after the construction, there is no grade separation whatsoever. The INDOT rep provided this response to my inquiry:
    Thank you for your e-mail regarding U.S. 31. I assume this is U.S. 31 and I-465 on the south side. The bridge replacement project is halfway complete, but on hiatus until spring (probably March or April, depending on when the weather breaks).

    The amount of shoulder at the bridge once replaced should be similar to what was there before. U.S. 31 is a limited access highway that has a high volume of traffic at higher speeds. It is suggested that pedestrians use local side streets with less traffic and speed to get to their destinations.
    US 31 is not a limited access highway by any stretch of the term; it is filled with intersections and stoplights, as well as businesses and private residences. In both cases, “limited access highway” allows a certain benchmarking for a LOS that completely removes pedestrians from consideration. And, contrary perhaps to the scenario in Carmel, we DO see pedestrians occasionally using the US 31 viaduct to get across I-465.

  17. cdc guy says:

    Off-topic rant of the day:

    I agree with Travis: the place to start is with parking lots. More shade, more-defined pedestrian paths, better connections to residential areas.

    One way to start is to stop with the ridiculously high parking requirements. Some of that parking-lot space could be re-configured to put a walking path in and among the parking spaces. For one take on this, go to Bing Maps and type in “Longwood Gardens, PA”. That layout has a central pedestrian path that probably costs less than 5% of the theoretical maximum parking, but it makes the walk in to the ticket lobby much more welcoming.

    If I were laying out parking lot regulations, I’d require such a path, and also put sidewalks between the head-in rows, to connect to the cross-lot path. (The surface parking lot at the Indianapolis Museum of Art has something like this, but it is oriented 90 degrees wrong; its central walkway inexplicably leads AWAY from the Museum’s entrance pavilion, parallel to the building front.)

    That’s probably the one thing that “lifestyle centers” get right: park once, and walk around in an inviting place between different stores. I’d grudgingly admit that’s a start.

    Pedestrians can deal with the relatively short interruption of the busy bridge or one busy intersection. It is because everything else on their journey is inhospitable and inconvenient that they really don’t perceive any alternative to using the car.

    Hmm. Maybe this wasn’t off-topic at all: more car trips to shop and do stuff in the ‘burbs means more road capacity is needed, means more bigger roads, means more parking required at stores…

  18. Dirt, that’s outrageous. Even if someone wanted to cross I-465 on a “local side street” how could they? By definition those are types of streets that do not get bridges across a major roadway.

  19. cdc guy says:

    Really, Aaron, what do you expect? INDOT’s self-defined mission is to move cars and trucks, not people.

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