SAFETY NY Thruway drops deaths 15%

SAFETY

NY Thruway drops deaths 15% — rumblers credited

The New York State Thruway (NYST) had 34 deaths in 26 fatal accidents on its 1026km toll system in 1966. The 34 compares with 40 deaths in 1955 — 15% down. Based on 13.6b vehicle/km travelled this represented a rate of 2.5 deaths/billion veh-km, under half the fatality rate for the interstate system as a whole (5.5 fat/b veh-km) and about a quarter of the rate for the whole US road system.

The 2.5 was a new record low for accident fatalities on the system and, confounding the fearmongers of the 'road safety' business, it coincided with the first full year of a rise in the posted speed limit from 55mph (88 km/hr) to 65mph (104km/hr). Data show posted speed limits have a negligible impact on average driven speeds in the US.

The Thruway attributes the 1966 improvement in large part to its completion of rumble slots just outside the edge lines of mainline lanes (see also TR#4 Jun 96 p7). The slots are dished depressions 16" (400mm) wide 1/2" (12mm) deep and placed a foot (300mm) outside the edgeline. They are ground out of the shoulder pavement and cost about 30c each or about $1,000/km. The whole New York Thruway system has cost only about $4m to edge-slot.

Fallasleeps12 to 2: Before the rumble slots were installed run-off-the-road or fall-asleep fatalities averaged 12/year, whereas in 1996 the first year in which the system was almost entirely edge-slotted there were only 2 fall-asleep deaths. The edge-slots last about 10 years (until repaving requires them to be redone) so the annual cost is about $500,000, suggesting that they save a life at a cost of c$50,000. In voluntary purchases of safety equipment and health care out of their own money American consumers are estimated to spend an average of $2 million/death averted and the EPA, FDA, OSHA and other agencies enforce regulations that cost $20m to $30m/life saved, so the edge rumble slots are bargain life-savers by comparison. Perhaps only the treatment of intersections with roundabouts rather than signals buys life-saving as cheaply.

The research to test various designs and specify the optimal rumble slot was peformed by the Pennsylvania Turnpike on an abandoned section of the mainline in the early 1990s. The trick is to design slots that will produce just enough noise and vibration in a truck cab to rouse a sleepy drive while not causing a dangerous amount of bumping and loss of steerability to an errant small vehicle such as a motorcycle. Similar success has been obtained by the Penn pike.

The Thruway says the next greatest thing it can do to reduce deaths is to improve the rate of seat belt use. Most of the 34 who died in '96 were not using their seatbelts and overall seat-belt usage was about 70%. (Contact NYSTA tel 518 436 2983 fx 518 426 3995)