Editorial: ‘Don’t die’ traffic signs hit the roads

“Don’t kill; don’t die.” It sounds like a pacifist’s rationale for conscientious objection.

But these days in Sonoma County, it’s what one might call the “direct approach” – at least as far as it goes for road signs intended to warn drivers to slow down. And the idea of pacifism on the roads isn’t that much of an exaggeration – because it’s getting to be a warzone out there.

Multiple fatalities in the past months on Occidental Road west of Santa Rosa, along with a rash of other high speed accidents in recent years, inspired the county Transportation and Public Works Department to put out a more dramatic missive to convince drivers to stay at safe speeds. “Don’t kill”; “Don’t die”; “Slow down.” That three-sign sequence of signs is cropping up these days on the county’s most collision-clad roads, as traffic officials try a novel way to send a message to local boy racers: Don’t become a fatality, commit vehicular manslaughter on our roads or both.

The days of school-bus-yellow “children at play” signs just aren’t cutting it anymore. Because if the idea of maiming Nerf-ball chasing tots isn’t enough to induce local leadfoots to ride the brake a little, it’s hard to argue that a 2-by-2 reading “you will die” isn’t worth a shot.

Madrone Road near Glen Ellen is among the dicey thoroughfares targeted for a sign; so is Bennett Valley Road, south of Kenwood, which has had so many accidents county officials are considering posting signs displaying its updated totals for accidents and fatalities. Sort of like one of those nonprofit fundraising “thermometer” billboards showing how close an organization is to reaching its donation goal – only in this case adding to the cause doesn’t enter you for a potential raffle prize, but a potential body bag.

Attention-getting marquees are all well and good, of course. But the larger question is: Will they have any effect? Can they make roads safer?

The answer is elusory, because the question is premature. We know of no doctoral theses demonstrating the effectiveness of “Don’t Die” signs, beyond their obvious results of prompting the occasional community newspaper editorial.

However, several studies have been conducted in recent years to gauge whether those larger electronic speed indicator signs – the Lite-Brite-style radar displays that read “your speed 46,” or whatever – ever inspire anyone to reconsider their speedy ways.

Attention-getting in their own right, those “show the driver their speed” signs should be a decent barometer of to what other provocative signage programs might aspire.

One of the more comprehensive studies released in 2010 by the Transport Research Laboratory in London placed 10 such radar signs throughout the traffic-heavy south-end, on various roads of varying traffic flows. The study found that the presence of what it called “speed indicator displays” produced an overall speed reduction of 1.4 mph on the 10 roads when the displays were working – no big whoop, you might say. But that number takes into account drivers who aren’t speeding in the first place – they have less reason to slow down. When the study looked at the overall proportion of drivers exceeding the speed limit before and after signs were erected, it found a 5.7 percent drop in vehicles driving over the speed limit when signs were active.

In other words, if there were 100 speed-limit breakers before the speed-warning signs were placed, there were 94 after they were placed. Huh.

And, the study continued, a 1.4 mph reduction in speeds across the board equates, according to statistics, to a 5.6 percent reduction in collisions.

The London study was shown to be fairly representational by similar later studies, which also showed radar signs having an overall impact of slowing drivers by between 1 and 2.5 mph, with a statistical drop in accident rates by 5 percent for every mile-an-hour decreased. That’s pretty much the best you can expect from speed signs.

Perhaps sensing an underwhelming reaction to the findings, in the study’s conclusion researchers made sure to point out that the 1.4 percent speed reduction was “better than no effect at all” – which is traffic-researcher speak for, “Give us a break, people, it’s better than nothing.”

If only slightly.

Because, the TRL report continued, with even the most effectively placed speed-reduction signs, the initial “novelty” effect of the speed-warnings lasted for only about a week. After that, fewer drivers were spooked by the signs, and speeds on those roads “slowly increased to previous levels.” After two weeks, the signs had virtually no effect on reducing speeds at all.

And further, the study showed, even during the one week when the signs did cajole drivers to slow down, their regard for the speed limit only lasted for about the length of a football field before they began flooring it again.

In other words, speeding drivers don’t change their ways just because a public sign calls them out – a reality that doesn’t bode well for the county’s “Don’t Die Don’t Kill” signage program.

Death, John Lennon once mused, “is just getting out of one car, and into another.”

Problem is, many of those drivers are picking up unwilling passengers along the way.

Email Jason at jason.walsh@sonomanews.com.