Tag Archives: speed bumps

Driving in the land of killer speed bumps

The in basket: I have written a lot about speed bumps, and speed humps and speed tables and their various approaches to slowing down drivers by requiring then to slow down or suffer anything from a rattle in the trunk to a broken suspension.

Generally I’ve addressed complaints about them from readers or ideas on how they can be made less disruptive.

I have been spending a lot of time recently in Cabo San Lucas, Mexico, and environs, and let me tell you you don’t know how good you’ve got it in Kitsap County.

The out basket: In Mexico, or at least in Baja California Sur, as the southern half of the Baja Peninsula is called, speed bumps/humps/tables are called “topes,” pronounced TOH-pays, and they will make you thankful for a mere speed bump, which is the worst of the three kinds in the Northwest.

There are two kinds in Cabo. The least objectionable are a series of round rises that run in a row across the road. In the states they would be called RPMs, for raised pavement markers, or, familiarly, “turtles.” They are, at least, not hard to see and not especially damaging if you hit them too hard. Many of the rows are missing a turtle or several and you can minimize the bounce by aiming for the gaps.

They can be deployed as they are in the states, but I’ve also seen them at the stop signs on two downhill legs of  a city intersection, forcing great care at the signs.

Then there is the other kind. They might be made of asphalt, concrete or even dirt. They span the roadway and are tall and painful to go over at a normal speed. Worst of all, little effort is made to make them visible as a variation in the road surface and there are no signs warning of them. They are devilishly hard to see at night.

I’m told it’s not unusual for passengers to yell out “Tope!!” when they don’t think the driver has seen one. Brake shops in Cabo must love them, as braking suddenly when you realize you’re about to cross one (or your passengers have just loudly warned you)

is a common experience. Still, that’s a lot better than hitting one at the speed limit. That could require an auto repair shop or conceivably, a body shop.

A main freeway through Cabo will be flanked by parallel access roads on each side, ingress and egress to which is regulated, as you see in HOV lanes in the states. You don’t have to worry about topes on the freeway, where the speed limit is 90 kilometers per hour (60 mph). It’s on the access roads that you’ll find topes and, perhaps as a result of the widespread destruction wreaked in 2014 by Hurricane Odile, they are often augmented by fearsome potholes.

I’ve been driven around the area so far, and haven’t had to watch for topes while behind the wheel. It’s a thrill I can’t say I’m looking forward to.

Bone-jarring park speed bumps widened

The in basket: Peter Madsen writes, “We were at Anderson Point County Park August 13, and I think that the county really got carried away with the speed bumps they installed. They are higher and more abrupt than any I’ve seen elsewhere, and even at dead slow speed our 2009 Accord bottomed out on the one next to the park entrance. So far it isn’t dribbling oil all over the place….

“Isn’t there some sort of a standard for speed bumps?” he asked. “More and more, your replies in this column strongly imply that there’s some federal or state standard for everything with regard to traffic. I’d think that the normal speed bump should be navigable by the normal average sedan without fear of damage. But those speed bumps are too abrupt and too high.”

The out basket: Peter e-mailed later that day to say a Facebook post from someone else said the bumps had been smoothed, and by the time I got out there, four of the five were widened to a comfortable level. But the fifth one, the one closest to the parking lot, was bone jarring. It was as bad as some you will encounter in some mobile home parks or the ones that were briefly in place at South Park Village Shopping Center in South Kitsap a few years ago before, I assume, shopper protest got them lowered and/or widened.

Doug Bear of Kitsap County Public Works, which did the work for the parks department, said, “The original speed bumps installed were not viewed as being effective in slowing traffic. They were built up, then residents and park visitors felt they were too abrupt. So the bumps were lengthened to create 12 feet long speed humps which are in place now. These conform to the existing county standard.” The fifth one was to be smoothed that day, he said.

As for standards for installing them, Jeff Shea, the county’s traffic engineer says, “Traffic calming devices that cause vertical displacement are usually called either speed bumps, speed humps, or speed tables.  Speed bumps are generally small and generally very abrupt.  They are used in parking lots quite often.  They are designed to force a vehicle to nearly come to a stop to maneuver over them. Kitsap County doesn’t use these on public roads.

“Speed humps are less abrupt, but do require a significant speed reduction to go over them comfortably.  They are normally spaced to allow motorists to achieve the posted speed between the bumps while decelerating and accelerating.  Speed humps are used by the county on local streets.  Speed tables are even less abrupt and are used primarily on roads that have bus traffic and larger vehicles on them.” Tracyton Boulevard has speed tables.

“The Manual on Uniform Traffic Control Devices doesn’t spell out how to build nor does it give specifications for the shape of the device,” Jeff said.  “The MUTCD gives the signing and marking requirements if speed humps or tables are used.

“The MUTCD doesn’t require signs, but recommends them with an Advisory Speed sign below the warning sign.  If (pavement) markings are used, it specifies how those markings should look and be placed.

“There is no federal requirement on the dimensions of a speed hump or table. Kitsap County tries to get their speed humps to about 3 inches (tall).  The width of the speed hump is usually about 12 feet. The speed humps can be formed into several shapes.”

Getting the humps to look as planned is a challenge, he said.  “Kitsap County builds their speed humps from asphalt. It is extremely difficult to screed the hot material into one of the shapes and compaction of the asphalt will impact the actual final height of the speed hump. This explains why speed humps around the county can vary in their impact to motorists.

“We could build them closer to the specifications, but that would take concrete.  Concrete costs significantly more and requires a much longer cure period before traffic can drive on it.

“A speed table is simply a speed hump with a flat top,” he said.  “The flat area is normally about 10 feet long.  The flat top makes if a little more comfortable for long wheelbase vehicles to maneuver over the device.  It also allows passenger vehicles to traverse a little faster than over a speed hump.”

I notice that the county’s signs warning of them call them ‘speed bumps’ and urge a 10 mile-per-hour speed to cross, though they really are speed humps. Bremerton’s signs say “speed humps” and urge 15 mph, though there’s not much difference in the two jurisdictions’ humps.

How about speed bumps on Valley Road?

The in basket: Merry McAllister of Valley Road on Bainbridge Island has renewed her campaign to make the road safer for pedestrians with a proposal for speed bumps. She learned via a previous Road Warrior column in November that there’s no likelihood of the road’s narrow to non-existent shoulders being widened for six years or longer.

“Could we get two or three LOW profile speed bumps on Valley, especially going downhill?” she asked in a new e-mail. “One could be at Parkhill, one at Kallgren, and another at Hyla.  Any of these would be appreciated. Maybe just start with one at Hyla, so folks get used to it and don’t start aeroplaning going down the hill.

“A sign saying ‘speed bump ahead’ always gets some attention, too,” she said. “Shouldn’t be too expensive.”

The out basket: I told Merry that most jurisdictions won’t approve speed bumps for arterials, and Valley looks like it would fall within that prohibition. But I asked the city about the idea.

K. Chris Hammer, the city’s engineering manager, replied, “Valley Road is classified as a secondary arterial street. (It) is traveled by nearly 3,000 vehicles each day, serving the Rolling Bay Town Center and connecting to many neighborhoods.

“The city has not placed speed bumps on secondary arterials and collector streets,” he said. “There are reasons for this. The primary one is that speed bumps themselves can present a hazard to the traveling public. Another issue is that emergency responders may have a good reason to travel at or higher than the posted speed limit. Maintaining response times to under 5 minutes for paramedics can be the difference between life and death and the severity of a fire can double every two minutes. Ambulances transporting the injured/ critically ill must slow to a crawl over speed bumps.”

Valley Road comes closer than many others to meeting a key measure of how appropriate the posted speed limit is, the so-called 85th percentile, according to the most recent speed study there.

“Designers must consider what speeds most drivers are comfortable driving on a segment of roadway and design the roadway to safely accommodate that speed,” Chris said. “This speed is known as the 85% speed (15% traveling faster, 85% at or lower) which in this location is 35mph, coincidentally the same as the posted speed.”

The 85th percentile is often slightly higher than the posted speed on other roads and highways.

“The city is looking to scoping a speed limit study of its 35mph streets and both Valley and Sunrise (the cross street in Rolling Bay) may be good candidates,” he said. “In 2013 we studied the 40-mph-posted speed streets and the speed zones approaching the Island’s town centers. One result was extending the speed controlled zone (lower speed) for the Rolling Bay Town Center further north on Sunrise.”

Does one have to comply with yellow speed signs?

The in basket: Barbara Westfall writes, “My husband and I are new residents in the Tracyton area.  When turning right onto Tracyton Boulevard from Bucklin Hill, there is a sign, two signs actually, on the same pole.  One says Speed Bumps, the other says 20 mph.  

“Now, does this mean you need to go 20 mph when going over the speed bumps, or is the whole road 20 mph until you are finished with all speed bumps?”

The out basket: The signs approaching the speed humps are yellow advisory signs that suggest a comfortable speed for crossing the rises, and can be ignored if you think otherwise. Speed limit signs are white with black markings and the one that says 30 mph just as you turn from Bucklin Hill Road onto Tracyton Boulevard establishes the speed limit throughout the stretch with the speed bumps. 

I was surprised to see the signs call them speed BUMPS. Those traffic calming devices are generally separated into speed bumps, the abrupt rises you see in mobile home parks, speed humps, the wider ones on most county roads and in shopping center parking lots, and speed tables, like those on Tracyton Boulevard, where the raised surface is large enough to contain most cars. The county must have decided drivers will understand the term speed bumps best.