Sunday, May 5, 2013

Hill Hopping isn't just about Judgment, it's also about Design

Those crazy kids. Accidents happen.

Last week's headlines about a student being impaled on a fence pole understandably grabbed a lot of attention. It was horrific. Fortunately there were no deaths.

There's a follow-up in yesterday's paper.

The "hill-hopping" is framed as a matter of driver safety education and poor judgment among teenagers and other newly minted drivers.

But it's also an engineering and design problem, not simply the vagaries of chance, accidental fortune, and poor judgment by the young.  Whether we are talking about suburban arterials or rural roads - and there are of course important differences between them - in too many cases it is all too easy to drive at speeds in excess of what is "reasonable and prudent."

A little over a year ago there was an article about the intersection of Orchard Heights and Doaks Ferry, and the same concerns about "catching air" were raised.
Richard Chesbrough who lives near the intersection thinks some drivers are tempted to push that limit when cars speeding east on Orchard Heights Road.

"They hit that steep rise just before the intersection and they catch air," Chesbrough said.
Sound familiar?

It cannot be repeated too much:  That design on Orchard Heights, the wide, wide road, is all about car through-put at 40mph, not about the safety of the walking and biking public or about the independent mobility of school children or others who might not wish to drive everywhere. It's about our roads as a fire hoses, pumping out cars.

To say the intersection is safe may also minimize the ways that roads are designed for speeds in excess of the posted limit, often designed for 85% of motorists to follow the limit. So here the road is likely designed for 15% of people to exceed the posted speed limit. Straight segments and broad avenues often implicitly encourage motorists to flout posted limits. We say and post signs with one thing, but design for another.

The same thing is true here on Ballantyne.  When we design for the 85th percentile, we are designing for 15% to exceed the limit!

According to the paper:
But in South Salem the temptation is there as urban streets quickly give way to less-traveled roads — many that have steep, rolling hills.

According to city of Salem traffic engineer Kevin Hottmann, there is no speed limit on Ballyntyne Road S, meaning the basic rule of 55 mph applies. The traffic control unit for Salem Police had not yet calculated the speed that the vehicle was traveling before it collided with about 300 feet of chain-link fencing, but police received unconfirmed reports that the car had been going about 80 mph....

“You’re taking a 2,000-4,000 pound instrument and accelerating it to get airborne,” he said. It’s especially dangerous, he said, if you’re a 16-year-old with limited driving experience. “Kids will be kids. At that age they believe they’re invincible.”
There's a common misunderstanding here.  The basic rule is not "55mph."  According to ORS 811.100 the basic rule is not a numerical default, and instead depends on judgment about what is "reasonable and prudent":
Violation of basic speed rule...(1) A person commits the offense of violating the basic speed rule if the person drives a vehicle upon a highway at a speed greater than is reasonable and prudent, having due regard to all of the following [list follows, which includes weather, visibility, width of road, etc.]
Given the limited visibility, it's highly likely that 55mph isn't prudent here under any circumstances!   Farm equipment or a stranded motorist could be on the road just over the crest of the hill - not to mention a person on bike.  55mph is certainly too fast for a lot of rural roads, but it's probably not difficult at all to drive the road at 55mph - until something bad happens.

Our roads are designed for speed and through-put. They are not designed for careful, and deliberate progress or for the safety of all road users.

And it's not just about speeding.  The expectation among drivers is for unfettered movement on hills.  As a commenter on another blog recently put it about the way people on bike impede autoists:
Driving to and from town can be a hazard when coming up behind a Cyclist barely moving up a hill in the car lane. Cyclists should lobby for Bike lanes on [a rural road] not only for their safety but also for the safety of motorists trying to pass them when they yield the road to motorists.
This isn't a person at all interested in "hill topping."  Nevertheless, the idea is that nothing, not hills, not people on foot, on bike, on horse, slow moving farm equipment - nothing should impede people in cars.  And when impediments arise, they should be designed out of the traffic lane and and moved out of the roadway for cars.

In fact, at times even the hills should be removed!

Under the doctrine of "forgiveness," because we want to design roads that "forgive" minor driver errors, an extreme solution is to smooth out the hills - just as we remove right angled turns and create more sinuous curves, just like we are doing on Market Street at Swegle.  Get out the grader and road cutting equipment.  Widen the road and smooth the curves and get anyone not in cars - or even slow moving cars - out of the way.  Let us go fast.

Market and Swegle:
Engineering "forgiveness" will result in faster speeds
So widening and hill-elimination is not going to happen here on Ballantyne, but would it be surprising to see rumble strips installed?

We should design streets for slower speeds and for all users of the road, rather than designing roads for higher speeds that "forgive" errors and hope drivers obey the posted speeds.


Curt said...

Even on local streets where our transportation policy clearly states that safety and livability are the top priority, residents dealing with speeding face a steep uphill battle to get things like speed humps and other traffic calming. If public works followed the policies exactly how they appear on paper, the default would be safety and livability and not speed and capacity like it is now.

We see it over and over again in Salem. The policies passed by council are treated like quaint obstructions in the relentless quest toward bigger, faster, more violent roads. Chopping trees, paving parks, and carving up neighborhoods are the default norms. City staff talk as if they have no control over it.

Angela said...

Thank you Eric.

The responsibility for safety is shared by all and the front line of those efforts should be traffic design.

Walker said...

Yes, this, exactly. The hydraulic metaphor is exactly where we are, cars are droplets of precious fluid to be conveyed as rapidly as possible to the destination, with all obstacles and constrictions removed, with the friction factors blasted away (you know, kids, bikes, walkers, etc. ... The detritus clogging up the works, interfering with more important cargoes ...)

This is the long and the short of it for Bridgasaurus ... Drivers sometimes have to Use Their Brakes! That is just Wrong, and we all know it.

One of the city council members from Vancouver BC used to give a slide talk and he'd show a picture of a ginormous land eating cloverleaf monster and say "and this is a left turn designed by a traffic engineer, which is to say a left turn you can do at 60 mph.". That's the mindlessness that's bringing us the chance to blow hundreds of millions on Bridgasaurs -- the religious fanaticism of the Sprawl Lobby for the Holy Sacrament of High-Speed Travel. Never mind that the problem, brief though it is, is already solving itself, and that all forecasts for diminished trip demand and higher travel prices will likely show that the existing network of roads (already too costly to maintain) is more than sufficient. the Sprawl Lobby demands a sacrifice, and they've selected the poorer and browner parts of Salem as the ideal sacrificial lamb for their rites.

Anonymous said...

In today's paper:

"A joyride on a road referred to as "roller coaster hill" ended in the death of a 19-year-old driver and two injured passengers Saturday night near Jefferson....

Both passengers told deputies that they had decided to go for a joyride on Valley View Road. They referred to the road as "roller coaster hill" because the road is primarily comprised of major hills and valleys.

Both passengers estimated [Nicolas Jolly was] going between 90-100 mph when he "caught air" on one of the hills, lost control and struck the power pole. No other vehicles were involved in the crash."

Anonymous said...

Here's another one, sad, sad, sad:

"A weekend bout of car-surfing has ultimately resulted in the death of a teenage girl, Salem Police have confirmed.

Police were called at 12:13 a.m. early Saturday to the parking lot of the Wal-Mart in south Salem at 5250 Commercial Street SE...

A group of teenagers were hanging out in the parking lot when three of them decided to go car-surfing, said Lt. Steve Birr. Car-surfing is a sport in which passengers cling to the exterior trunk of a car while another person drives it. They were in the midst of car-surfing when two teenagers were thrown from the trunk of the vehicle.

...17-year-old Marisal Quesada of Salem, suffered life-threatening injuries and was transported to Oregon Health & Science University.

Quesada died of her injuries at approximately 5 a.m. Monday morning, Birr said."

Maybe a large parking lot isn't so clearly a design issue, but in a way it is. Of course it's also a judgment thing, too.