A Naptown Numbers theme is that laymen should be skeptical of what experts tell them; credentials are no substitute for clear reasoning. In this post we suggest a related rule of thumb: we’re more often right than wrong when our default assumption is that “studies” don’t prove what they’re said to prove.
This suggestion is prompted by testimony given during the February 20, 2024, Roads and Transportation Committee meeting of the Indiana House of Representatives. Jennifer Pyrz, the acting CEO of the Indianapolis Public Transportation Corporation (“IndyGo”), was speaking in opposition to Indiana Senate Bill 52 (“SB52”). SB52 would impose a temporary moratorium on appropriating street lanes for exclusive bus use and in particular on appropriating lanes of Indianapolis’s Washington Street for exclusive use by IndyGo’s proposed Blue Line. The Blue Line is to be the third of three so-called bus-rapid-transit (“BRT”) routes in the IndyGo system.
Having presented her credentials as “a Purdue-educated civil engineer” who she said has a “professional responsibility to understand the technical aspects of the Blue Line project,” she implied that there’s no need for the further consideration that SB52 would provide time for:
It has been suggested that this bill is necessary to allow time to study the impact and effectiveness of dedicated lanes. Those studies have been done. They have been done locally, nationally, internationally, and specifically for the Blue Line. Engineering analyses along the Blue Line corridor have shown that dedicated lanes will reduce crashes along the route and will not significantly impact vehicular traffic.
Citing studies and waving credentials is a commonly used way of discouraging independent analysis. Engineering analyses have been done. Ms. Pyrz is an engineer. Laymen should just accept the resultant conclusions.
“I’m confident in the engineers,” state representative Ed DeLaney subsequently said, apparently without bothering to determine whether the studies Ms. Pyrz cited were any good or whether she had described them accurately. Of course, citizen legislators can’t possibly vet every study that might be cited to them. But the rule of thumb we suggest here is that it’s best to give no weight to studies we haven’t vetted.
A study that dealt with IndyGo’s Red Line, its first BRT route, provides an example of why this is so. Here is what Ms. Pyrz had to say about it:
A recent analysis of Red Line conditions found that where dedicated lanes are in place on College Avenue and along Meridian Street there were nearly 40% fewer crashes in the three years following the Red Line opening than in the three years prior to its construction. Additionally, vehicular speeds on those two roadways were actually slightly higher with the dedicated lanes: two to eight miles an hour.
Crashes down, speeds up just a little bit. . . . Dedicated lanes are safer for all roadway users and will have little overall negative effect to vehicle traffic.”
As we reported in a Naptown Numbers post published before the committee meeting, Ms. Pyrz had cited that study previously, during the IndyPolitics.org interview in which she misrepresented IndyGo’s mixed-traffic travel time to the airport. Not having seen the study, we couldn’t conclude much about it in that post. But we speculated that the loss of travel lanes had made the corridor no safer, that it had merely shifted traffic and the attendant crashes from Red Line streets to others.
After obtaining a public version of that study’s report, we’ve now found that our speculation was probably correct. (We say “public version” because some of the data we would have expected is missing, as though information from an internal version had been expunged.) Although Ms. Pyrz studiously avoided divulging crash rates to the committee, four crash-rate values were perhaps unwittingly left in the version we read. And they reveal that Ms. Pyrz’s testimony was misleading.
True, the report indicates that the number of crashes fell by 38% with the advent of dedicated lanes:
But the four crash-rate values in the excerpt above indicate that the number of crashes per million vehicles increased by 3%; a 5% increase on Meridian overwhelmed a 1% decrease on College. So, contrary to the impression Ms. Pyrz seemed determined to convey, car occupants on those streets are no safer now than they were before dedicated lanes; if anything, they’re less safe.
Had Ms. Pyrz wanted to give the committee a more-complete picture, she might additionally have provided bus-specific safety data such as the preventable-accident numbers excerpted above from IndyGo’s most-recent board report. (“Fixed route” in that excerpt refers to all regular IndyGo buses but not to the special vans it uses for qualified handicapped passengers. Instead of following fixed routes, those vans go where passengers direct them.)
Although preventable-accident rates vary greatly from month to month, the disparity exhibited by the numbers above for January 2024 isn’t especially atypical; over the past twelve months the average for the BRT route has been 3.8 times as great as the average for fixed routes generally. In other words, IndyGo’s BRT buses have been much more accident-prone than its other buses. Now, this may have more to do with the type of buses the Red Line uses than with the fact that they travel in dedicated lanes. But it does suggest a positive effect of delaying replacement of the buses that currently travel Washington Street with the more-accident-prone type that the Blue Line will use.
Returning now to the Red Line study, we note for the sake of completeness that it found crash reductions not only on the Red Line route but also on streets where no lanes had been dedicated to buses. In the latter case the reductions were decidedly smaller, but we can’t infer anything about relative safety from those findings, because corresponding rate values didn’t make it into the report. Again, the public version of the report omits data we would have expected to see.
But in light of the report’s crash numbers the rate values that did make it into the report imply that dedicated lanes throttled traffic volume back by 39%. Ms. Pirz’s conclusion that dedicated lanes “will have little overall negative effect to vehicle traffic” may have given a rather different impression.
As to vehicle speed, the report did find an increase along the Red Line corridor, although where Ms. Pyrz got the “eight” in her “two to eight miles an hour” is a mystery:
But Ms. Pyrz didn’t tell the whole truth. Missing from her presentation was the study’s finding that speeds increased similarly on streets that don’t have dedicated lanes:
The facts she omitted reveal that it’s hard to attribute speed increases on the Red Line corridor to eliminating travel lanes. We hasten to add that the report nonetheless attempted to do so. But its logic fell far short of syllogistic, so rather than attempt to describe it here we invite the reader’s independent attempt to discern any logic we missed in the report’s Sections 3.1 and 3.2. In that connection all we’ll mention is that the report gave no evidence for the traffic-volume reduction it speculated might be the cause of other streets’ speed increases, and Indiana Department of Transportation data say that to the contrary total vehicle miles traveled on Marion County city streets actually increased.
In summary, we’ve seen that IndyGo misrepresented dedicated lanes’ safety effects. As we saw in the last post, moreover, the Federal Transit Administration’s and IndyGo’s own data reveal no significant speed or reliability advantages of dedicated lanes; all we have are IndyGo’s claims, which time after time have proved unreliable. As the committee meeting demonstrated, however, much of the public is still laboring under the misconception that dedicated lanes make bus routes faster, more reliable, and safer.
So whatever studies Ms. Pyrz thinks have been done haven’t made the public or the General Assembly any better informed about dedicated-lane realities. As we’ve pointed out in several previous posts, IndyGo and other special interests have on the contrary worked tirelessly to create the misapprehensions so evident at the committee meeting. Before Indiana loses any more lane-miles to city buses the General Assembly needs time to get past the IndyGo-created misinformation fog and consider the objective facts that actual data reveal about dedicated lanes. In doing so it would be well-advised to be skeptical of appeals to “studies.”
Misrepresentation of "studies". It's an epidemic.