TRIP trips

Highways certainly need some more powerful advocacy in Washington DC. The Secretary of Transportation Federico Pena keeps saying we can’t build any more roads and it is almost a conventional wisdom in the national capital that new highways won’t do any good. They’ll just get filled up right away. (Tell that to Michael Crane CEO of the Dulles Greenway!) Everyone here says we have to do more transit, and in the prevailing anti-highways culture the transit lobby extracts about ten times the amount per passenger from federal transportation funds as does the highway lobby.

One group that labors to be a voice for highways is The Road Information Program (TRIP) but that outfit needs to be careful with its credibility. One example — TRIP claims in a recent publication that: “The Federal Highway Administration found that when two-lane roads were upgraded to four lanes with a median, highway fatalities decreased by 71%.”

Nearly three-quarters! Yes, that caught our eye. Pretty powerful ammunition in the battle for roads money we thought. Something that would help put us highway-enthusiasts on the moral high ground, and worth some more publicity.

Only trouble is it doesn’t hold up. TRIP tells us that the 71% number comes from the 1995 Annual Report on Highway Safety Improvement Programs (FHWA-SA-95-033 page IV-7) where it is a description of the calculated reduction of fatalities from safety improvements in the category titled “Construct Median for Traffic Separation.”

Nothing there about projects in which two lanes was expanded to four lanes to get a median. It just says a median was constructed. We called the office that compiled the report and an official there confirmed these projects only involved installing a median, not road widening. No more lanes, which makes the number 71% even more extraordinary.

The official said the projects generally involved taking a present high accident arterial roadway paved flat curb to curb with simple stripes in the middle and replacing the striped middle with a curbed and raised, usually grassed, median. He suggested for more details we contact some of the state highway agencies that built such improvements, though he said he thought they were mostly quite a long while ago, many in the 1970s. The FHwA table shows the calculation of 71% fatality reductionwas based on $64m worth of such median building projects over a 20 year period. Now $64m worth of projects is a pretty small sample. It will surely be dangerous to project possible outcomes from a small number of special safety projects that the states sponsored for federal funding. Unrepresentative of highways in general.

We do know that expressway standard roads have a fatality rate per vehicle-mile 40% to 45% below that of other principal arterials (around 1.2/100m vehicle-mls compared to 2.1) in rural areas and 55% to 60% below in urban areas (0.7/100m v-mls vs. 1.6). TRIP too quotes numbers like this. But an expressway has a whole slew of safety improvements over an ‘other arterial’ to achieve those kinds of reductions in fatalities — control of frontage access, grade separation for crossing and turning traffic, longer sight lines, higher design speed, pull-off shoulders, merge and diverge lanes, more guardrails, top quality signage, more clearance from structures and usually not merely a median but a whopping median barrier as well.

In that context the suggestion of a 71 percent reduction of fatalities being typically achievable by simply installing a median plus widening just doesn’t stack up with the broader data, and any FHwA suggestion that 71% less death will be possible simply by sticking in a median looks like an absurd extrapolation from an unusual little bunch of unrepresentative projects. (Contact TRIP 202 466 6706, FHWA Office Highway Safety 202 366 2157)