Maintaining a Safe Following Distance

This is a great column on a very thorny subject. Everyone loves to moan about how impossible a 2 second tailback distance is, but the fact remains that the gas pedal works both ways, and momentary speed corrections to re-create your space margins actually generate virtually zero increase in trip time, but a huge and very significant increase in both safety and peace of mind.

What we know, however, is that regardless of the very well established knowledge on the point, no driver population around the world maintains a 2 second margin on average. Australian research found a range of .5 second to 1.7 seconds. The further question then is why we aren't crashing into each other in much larger numbers than we are, and the answer to that lies in the second "Key Defence" (to quote the Canada Safety Council) - Eye Lead Time. Effective attending and adequate forward vision are the critical variables keeping people out of each other's trunks, to the extent that they're in play. And we know from the Naturalistic Driving Studies that they're actually not in play to the extent we'd prefer, so the take-away from the research is plainly that an astonishing amount of the successful driving out there is down to the simple good fortune built in to multivariate systems.

This is where the pragmatism of Vision Zero offers tremendous potential  - recognizing that people do, and always will, screw up as we drive, we need to ensure that the traffic system has adequate fail-safes built into it. So, for instance, the absolutely critical point that vehicle speeds should be regulated to reflect relative potential injury severities in each scenario, rather than the simple speed habits of average drivers. As well, the emphasis on increasing the safety capabilities of vehicles, with systems like forward crash prevention, is again built on the understanding that there is a need for the vehicle to fill in the performance gaps of it's driver:  "the sensors are always on, monitoring the environment, even when the driver isn't".

Increasingly, we are seeing technology fill in the gaps in human performance, with commensurate reductions in carnage. But recent upward trends across North America in crash and injury rates are telling us that we can't afford to allow vehicle technology alone to solve the problem  - there is a pressing need to address the issue of de-regulation of the traffic environment,  and dis-regulation of driver behaviour. The speed limit increases that have been the trend over the past several years have had the obvious and predicted results: commensurate increases in crash frequencies and injury severities. Speed limits will need to be reduced, and those reduced limits considerably more enforced, if we are to reap the benefits of other safety measures.

This brings us on to the problem at the end of the article  - few tickets for space margin violations, relative to speeding tickets. Fact is, vehicles on average are consistently moving at roughly 10kms/hr over the speed limit, which we know generates a crash risk approximately equal to driving while .08 impaired. This means that dirvers are both more likely to crash, and also that the crash will entail more serious injuries. But, there simply cannot be enough enforcement of either speed or space margins while we rely only on police officers in police vehicles.

This is where technology has massive untapped potential in our province  - automated enforcement, anathema though it is to many, is nonetheless the obvious way forward, as proven in jurisdictions around the world that are posting dramatically lower rates of serious injury and fatality than we are. What can and should be rcognized is that systems like red light cameras are both significantly reducing the health care budget demands imposed by traffic collisions, and also capable of so much more. A single camera can accomplish red light monitoring, license plate monitoring re: stolen vehicles, driver behaviour monitoring re: distraction, and vehicle spacing and overspeed infractions, to name the most obvious few. A substantial increase in our use of available technology for vehicle/driver monitoring absolutely will reduce the carnage on our roads, if we will but acknowledge that lives saved is the goal, not lives wasted on "freedoms" to do whatever we bloody please behind the wheel. 

So  - safe margins, an essential goal. A goal that can, is, and will be better achieved by driver assistance technologies than by simply excoriating the legions of "tailgaters" out there. But still, only actually "safe" within the context of a safer traffic system that includes safer speeds actually commensurate with relative hazard of the road environments, and considerably more (and inevitably automated) enforcement of safety regulations. 

Thanks for the column - this was fun!

Cheers

Bill