Our Urban Challenge: The Numbers Game

The Holy Grail of bicycle advocacy is numbers of kiesters in saddles on two wheels on the road.

Some advocates are willing to do almost anything to increase participation — including putting novices in danger.

There’s a “but”: It appears rather clear that the more people who ride bicycles in a given area the safer it is to ride a bicycle on the road (convincing novices that the riding in traffic is already safe requires education). A new study recently published in Environmental Practice reinforces the safety-in-numbers thinking and adds a bonus: More people on bicycles makes the traffic system safer for all road users.

There’s another “but”: It appears that bicycle lanes play a minor role in encouraging people to ride bicycles (hoo-ray for that). This new study suggests that narrow streets, a dense grid pattern, and traffic calming are the real keys in the American context (or, in the case of this study, the California context).

Today I want to discuss one of the findings: intersections per square mile. The study shows that safer, high-cycling cities have more intersections per square mile than do less-safe, low-cycling cities. Safe, high-cycling cities in the study averaged 114.2 intersections per square mile suggesting a dense grid pattern. The following graphic illustrates common street patterns. It’s easy to see why grids have more intersections and why grids would tend to calm traffic.

Now let’s take a look the square mile at the heart of downtown Springfield (defined by me as the area surrounding Park Central Square).

That’s a rough estimation using Google Maps. By my (very rough) count using this map, downtown Springfield has 127 intersections in this square mile. Further, the speed limit is 20 mph on most of the roads you see there (exceptions include Grant, Jefferson, Kimbrough, Benton, and Chestnut Expressway).

The four safest cities in the study share something else with Springfield, but the study does not mention it — and I think it is important: The safest cities are all home to universities — Berkeley, Chico, Davis, and Palo Alto. On this Springfield map, MSU is just off the southeast corner, and OTC and Drury intersect the map to the north and northeast.

I’m only discussing grid density now. But this begs the question: Why, then, has Springfield not achieved the kind of bicycling numbers as, say, Davis, California? We have active advocacy (STAR Team) and a cooperative (even enlightened) public works department and police force. We have encouragement and education programming. While facilities such as bicycle lanes play a minor role according to the study, we have some of those, too. That square mile area has several bicycle lanes plus a growing greenway.

I think one important reason we’re not seeing the kinds of bicycling numbers as those California cities is because there are damned few employers of the kind that attract the creative class (notice the income data in the study). Yes, we have entertainment — mostly at night. Yes, we have a growing number of lofts. Yes, MSU is moving into more and more downtown buildings (e.g. Park Central Square Office Building, Jordan Valley Innovation Center, Brick City). Yes, there are banks and churches and stores and restaurants and other small businesses. But there are precious few large employers who employ highly-skilled, creative people of a kind that MSU, Drury, and OTC attempt to produce.

In short, the reasons to bicycle downtown right now are largely confined to after business hours (re: my first post today).

Our urban challenge (one of many): Encourage more employers of the creative class to move downtown. MSU’s movement into downtown is a great start. Now others must follow. Tax breaks help bring employers. Can we, however, save these breaks for employers that bring high-wage creative jobs to town instead of employers who bring low-wage, low-benefit jobs to town.

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Comments 7

  1. Steve A wrote:

    “…rather clear that the more people who ride bicycles in a given area the safer it is to ride a bicycle on the road”

    Really? Has Jacobsen now applied the null hypothesis or actually attempted to establish some cause-effect relationship recently rather than tossing out some theory without ,presenting even a pretense of supporting data?

    While I agree that higher cycling numbers are good, I’m surprised to see Andy uncritically accept such shoddy research.

    If Springfield wants higher cycling share, it simply needs to stop subsidizing motorists at the expense of non-motorized transport and to remove dangerous motorists from the traffic mix. Higher numbers are an effect of perceived safety, not a cause.

    Motorists rarely run into cyclists that are operating safely and predictably whether those are few or many.

    Posted 02 Jul 2011 at 2:15 pm
  2. Andy Cline wrote:

    Steve… The study in question makes a good argument for safety in numbers by suggesting that the numbers occur because of grid density, lane narrowness, and traffic calming. It could be these things that create the safety and the numbers, then, that reinforce it. This study is partly about investigating the safety in numbers idea. I think they have an interesting take worth discussing.

    I may be guilty of overstating it 🙂

    I would be interested in some detail re: “shoddy research” — or do you mean to indicate Jacobsen? This current study looks fairly solid to me. I could certainly be missing something.

    re: “If Springfield wants higher cycling share, it simply needs to stop subsidizing motorists at the expense of non-motorized transport and to remove dangerous motorists from the traffic mix.”

    *head-slap* I’ll call the city council first thing Monday. Who knew it would be that easy? 😉

    Posted 02 Jul 2011 at 2:33 pm
  3. Phillip wrote:

    I believe that Springfield’s climate versus that of Berkeley, Chico, Davis, or Palo Alto might also play a part in this equation. When I account for the fact that Springfield’s record temperature range is over 140 degrees, with the lowest temperatures below -25 and the highest temperatures above 115 degrees, I’m making some different choices than I would if I lived in California. I doubt the possibility of ice, snow, slush or sub-zero temps are ever a consideration for their lifestyle choices or purchases. I must admit that I’m a wimp, and if it’s below 40* outside, I’m probably driving my truck. At least until economic factors dictate otherwise.

    Posted 04 Jul 2011 at 4:11 pm
  4. Andy Cline wrote:

    Phillip… Yes, I’ll bet climate plays a role. But there are one or two weeks a year when it’s not too bad 😉

    Posted 04 Jul 2011 at 4:51 pm
  5. Khal Spencer wrote:

    Steve, did you open the link? This is a new paper, not the Jacobsen paper.

    Posted 05 Jul 2011 at 4:06 pm
  6. Wes Marshall wrote:

    Thanks for taking a closer look at our work Andy… and yes, you are exactly right in saying that there is a lot more to finding both high bicycling and good safety than simply adding bike lanes.

    Some other thoughts I’d like to throw into the mix:

    While I agree that there are some self-selection & biking culture benefits in some of these college towns, the city still needs to have the supporting infrastructure. At the same time, building what seems like the appropriate infrastructure does not guarantee biking either (in other words, we don’t have enough information to disentangle a causal relationship). And with climate, it clearly plays a role; but there are also plenty of examples of high bicycling taking place in cities with far harsher weather – such as Minneapolis and Boulder – than these California cities.

    In terms of intersection density, it is difficult to compare our citywide numbers to a single square mile of a city like Springfield, Missouri. So putting a number like 127 intersection/square mile against the 250 to 300+ intersections/mile in the areas in and around the downtowns of our high biking cities doesn’t really explain everything that is happening here with overall community design. Here are links to a couple of my other papers that better explain street network design and street design characteristics in terms of safety (http://trid.trb.org/view.aspx?id=1097732) and mode choice (http://trid.trb.org/view.aspx?id=909985)…

    Posted 05 Jul 2011 at 10:50 pm
  7. Andy Cline wrote:

    Wes… Thanks for your thoughts.

    Agreed re: 1 square mile. I do not mean that to be exhaustive. But that is our most active square mile in terms of bicycling. I offer it FWIW. And thanks for the links!

    Posted 06 Jul 2011 at 9:04 am