1. Engineering: What? I’ve built speed bumps (admittedly, this was some years ago). It involves shoveling asphalt in a vaguely straight line and then running over it a couple times with a roller. They don’t last forever, without maintenance. What does?

2. Snow plows: Generally, in snow areas, you also install signs that say “BUMP” or equivalent. In addition to warning speeders to slow their butts down, these also cue the plow driver to raise the blade a foot.

3. Effectiveness: Very high. Deployment leads to lots of complaints from people who were driving too damn fast in a residential area. Since this is the ‘Flats, I have to confine my comment about that to “Oh, that must be distressing to you”.

4. Mis-use: Yes, this can happen. When I lived in San Jose, there was a street near me that was, I guess (I didn’t use it to commute, so I guess), used as a shortcut around a piece of Almaden Expressway. The first incarnation of traffic calming involved a stop sign at every cross street and two speed bumps between each stop sign. I drove on the street occasionally to reach the houses of some of my kid’s friends. It was slightly irritating, but infrequent. After a year or so, a couple of the stopsigns, and all but one of the bumps, had disappeared — the locals found it much more irritating than I did.

5. Equilibrium — see 4 above. Leave it up to the locals. They have to drive over the bumps much more frequently than anyone else. You really don’t need many. You’re usually trying to persuade people that do not live in the neighborhood that the correct speed in a 25 mph zone is, maybe, 35 mph, but not 60.

6. (Optional) Kinetic Energy and response time — this is just a bonus physics remark for anyone who cares. There are two reasons why speed bumps are effective.

(1) Kinetic energy is proportional to the square of velocity (speed). If you are moving and hit something that is unmoveable, the amount of energy that you have to absorb goes as the square of your speed. This is why hitting a wall at 25 mph causes damage, and hitting it at 50 mph (absent air-bag) will turn you to jelly (4x the energy). Hitting a speed bump isn’t the same as a wall, but the square of speed factor is still significant.

(2) Mechanical response time: A motor vehicle has a suspension, which involves large springs and shock absorbers, which are gas-filled pistons intended to damp out the the bouncing that the springs would otherwise produce. If you hit a speed bump at excessive speed, the shock absorber piston cannot respond quickly enough (this roughly why belly-flops hurt), so the entire jolt is transferred to the springs and the chassis (that is, the passengers).

Generally, a speed bump will not damage your vehicle, even if you fail to notice it coming. But I personally think that it has a much greater behavior-modification capability than a rumble-strip. I quite like rumble-strips, but their intended audience are those folks who want to drive safely but may be distracted or sleepy or momentarily inattentive. Speed bumps are addressed to those who think saving a few seconds or minutes of personal transit time is more important than the safety of the local fauna (dogs, moose, elementary schoolkids, etc.).

We also have them in town –across the entire lane– at the approach(es) to some intersections and in large parking lots where folks tend to fly from one area to the other without regard to/for any *other* traffic / activity in the area.

Also too at 4-way stops out in the sticks where, depending on the height of the crops, you can’t see traffic approaching the intersection from the other roads.

The across-the-lane rumble strips are set up in 3s – the first one you come to is narrow, the second is a bit wider, and the third is widest. Between the strips, and at the intersection, itself, there’s a ‘regular’ patch of roadway — so, you’re tooling on down the road and all of a sudden your car goes ‘grumble-dy-grumble-dy’ with shimmies. Then it rides smooth again…then ‘grumble-dy, grumble-dy, grumble-dy’ with shimmies; then smooth and then ‘grumble-dy, grumble-dy, grumble-dy, grumble-dy’ with more shimmies, then voila!, you’re at the intersection, all slowed down and prepared to stop. i just think they’re so neat! (Yes, I’m weird that way…) beth.

I’d imagine leaving a section ‘nekkid’ for a bike tire wouldn’t be all that difficult when planning them across the width of an entire lane. And yes, they ARE noisy – but that’s one of the points of them. When tires ride over the rumble-stripped section, the whole car makes a distinctly different ‘grumble-dy, grumble-dy’ noise! and the whole car shimmy-shimmy shakes… there is NO doubt that your attention is being called for/grabbed. Personally, I love the things! beth.

One of the objections to speed bumps is the noise; I can’t imagine that rumble strips are any worse in that regard.

I would think that speed bumps would be torn up by snow plows (but what do I know about snow plows? On the other hand will top 100 degrees here this afternoon…). There are lots of other options – the best are those that cause drivers to pay attention to something at a shorter distance. The farther ahead you are looking, the faster you feel comfortable going. Something as simple as waving to strangers as they drive by can work – as will interesting roadside art, the presence of someone sitting in their yard reading, or an intersection that has a different type of color of pavement (as all the upscale shopping center developers have apparently figured out now). In Portland there are intersections that have the centers filled with painted medallion designs. We all know that a roadside accident scene works amazing well to slow down traffic. Not that I’m recommending that one – but you see that anything that brings the drivers focus back to his or her immediate surroundings will help calm traffic. There was a Dutch neighborhood that put used furniture out in the street to create their own traffic calming system when the city was slow to respond to their needs… a nearby street did the same thing here with trash carts for a while.

This website has a lot of good info and links, although I haven’t looked at in a while so I’m not sure what all is there…
http://www.lesstraffic.com

Still, at some point you do need the city to come in with things like chicanes and the like – and hopefully work with the residents to find a good solution to the local situation.

Y’know, it’s one thing to ‘hear’, second hand, about the whackadoodles who’re advocating a violent overthrow of this government [and to 'hear' about the names they call POTUS and the administration], but its another thing, entirely, to be considered one of ‘them’ and to get emails/links to messages that’re blatantly calling for ugly, ugly, ugly. Along with feeling disgusted and alarmed, I feel oddly ‘dirty’ that I’ve been exposed to that ugly. beth.

Over the past 5-years, they’ve all been removed — all but one. The rest of the areas, the places where the speed bumps used to be, have all been replaced with ‘rumble strips.’ Law enforcement likes them because they do their job in getting drivers to slow down where they are supposed to [slow down.] And the city elders are happy because the road maintenance budget for replacing worn down, cracked and/or broken speed bumps is now not a worry – there’s just that one left…and when it goes ‘rotten’, it’ll get replaced by rumble strips, too.

I don’t know if Anchorage’s climate/road conditions would make milled-in rumble strips a viable safety mechanism/option for traffic control, or not, but they sure have worked well here; as far as warning drivers to a potential congested and/or ‘watch out’ area, they are waaaaaay better than speed bumps ever were. I’m also –obviously– not familiar with the roadway section/area in question, but surely with an already in-hand $350K, *something* could –and should!– be done to alert drivers of potential ‘problems’! Would milled-in rumble strips work? – could they be given as a suggestion to Mayor Sully? beth.

Rumble Strips – Frequently Asked Questions [State of Alaska]
http://dot.alaska.gov/stwddes/dcstraffic/rumble/rumble_faqs.shtml