‘Motorists give speed limits short shrift’November 8th, 2008 - 2:43 pm ICT by IANS
Washington, Nov 8 (IANS) Motorists cynical about speed limits tend to violate them as long as they don’t get caught. “So the faster you think you can go before getting a ticket, the more likely you are to think safety’s not compromised at higher speeds,” said Fred Mannering, professor of civil engineering at Purdue University.
Mannering used a series of mathematical equations in “multinomial logit models” to calculate probabilities based on data from a survey of 988 motorists in Tippecanoe County, Indiana, where Purdue is located. Findings generally agree with other data taken in recent years.
“For whatever reason, respect for speed limits seems to have deteriorated,” Mannering said. “A 2002 survey indicated two-thirds of all drivers reported they exceeded the posted speed limit, and roughly one-third reported driving 16 kmph faster than most other vehicles.
“These figures are even more disturbing when you consider that they’re self-reported and likely to be understating the degree of speeding problems,” he added.
The Indiana survey participants were asked: “At what point do you feel speeding becomes a threat to the personal safety of you and your family?” The motorists were given three choices: eight kmph, 10 kmph or 20 kmph over the speed limit, said a Purdue press release.
Of the 988 drivers surveyed, 21 percent thought it was safe to drive up to five kmph over the speed limit, 43 percent thought it was safe to drive up to 10 kmph over and 36 percent thought it was safe to drive up to 20 kmph over the speed limit.
The survey was taken before and after a 2004 media campaign stressing the dangers of speeding that included radio and newspaper messages.
Using survey data, Mannering applied a series of mathematical equations in a model to estimate the probabilities of speed and safety viewpoints for drivers in various categories.
The findings are detailed in a study appearing in Transportation Research Part F: Traffic Psychology and Behaviour.