Speed Humps (Plymouth)

[bubzki2]

Hello all, this is basically a call for advice and aid relating to what I view to be unnecessary speed humps near my brother's house in Plymouth. They're located near the south shore of Medicine Lake on South Shore Drive, between Peninsula Road and 13th Ave N. I'm trying to get a petition together to get them removed once and for all. Plymouth currently has a moratorium on "new" speed humps, but they ignored that and reinstalled them in 2010.

Does anyone have literature or studies showing the effectiveness or value of speed humps on a 30 mph road? Can someone help guide me to get these removed? I've contacted Bob Stein, the relevant Plymouth city council member, Jim Renneberg, the assistant city engineer and, while somewhat helpful, I feel like I'm still hitting a dead end.

Any assistance would be greatly appreciated!

[mulad]

What speed do you need to go down to in order to go over the humps? In that residential area without any sidewalks, I'd be inclined to reduce the speed limit to 20-25 mph anyway, or at least put up some advisory speed signs to that effect (and I see that the speed limit is indeed 20 mph along Peninsula Road in Medicine Lake, according to Google Streetview). I don't mind speed humps as long as they're set to match the speed limit or have some advisory speed posted so I know what to expect ahead of time.

[bubzki2]

You have to pop into first gear to clear some of them - think 5-10 mph. It's already a narrow street so you don't feel inclined or comfortable going faster anyways.

I talked to the city of Plymouth, they said they can't change the speed limit - otherwise I'd argue for a 20-25 mph limit. Sounds really complicated to get the state to drop below 30. Recommended signed speed in 10. They were originally installed in 1995 when the Flying Tiger and Country House bars were booming. The Flying Tiger burned in 1996 and the Country House faded around 2000. These were reinstalled in 2010 well after they had outlived any usefulness.

[bubzki2]

Well, I take it there's not going to be a panacea as I'd hoped. Apparently there's one resident on this street that dictates what everyone else will do.

I'm toying with filing for an injunction against the City of Plymouth, but that would be a very long process. What I really would like to do is get the City and the State to agree to change the speed limit to 20-25 while removing the humps. Funny, though, someone with knowledge of the situation said if that one bad apple wanted the humps gone, they'd probably be gone in a week.

[QuietBlue]

I'd be interested in any good resources on speed humps as well. My HOA recently installed temporary ones on my street (when the speed limit is already 15 MPH), and these things are very steep, almost more like parking stops, and even 5 MPH is too fast to go over them -- you pretty much have to crawl over them at 1-2 MPH.

I don't mean to hijack the thread, but just wanted to encourage anyone else with knowledge or resources about the subject to share it.

[bubzki2]

Thanks for the reply! No, don't worry about hijacking - I basically know my odds are nigh impossible. Nevertheless, I think there is a dearth of studies done on the effectiveness of bumps and humps and much like the FAA's silly cell-phone prohibition, I almost feel that it's planned ignorance.

However, your situation is very likely different than mine in that you simply have to convince your HOA powers that be that they should remove it. Less bureaucracy, I'd think compared to tackling the city of Plymouth. A common complaint in general is inadequate marking of bumps and humps. In my case, they were originally given advisory speeds of 20, but then a school bus went over at 20, injuring children who hit their heads. The next day, the signs said 10. Nevermind the impact these have on emergency vehicles and snow removal...

[QuietBlue]

I thought some cities actually had prohibitions on speed bumps unless they were on private property because of concerns about the effectiveness and possible liability (as well as the concerns you mention about snow removal and emergency services). I'm not opposed to low speed limits for residential areas at all, I just don't think that speed bumps/humps are always a good solution.

[PhilmerPhil]

FWIW, Minneapolis was going to lobby the state to change the laws to allow individual municipalities to have more flexibility on lowering speed limits below 30 at the same time they lobbied for the other changes for biking, like no stopping in a bike lane. For some reason, the speed limit part of it, which has such potential to be a gamechanger for urbanism, was dropped out. Hopefully this comes back next year.

[bubzki2]

Well, that does seem to be the biggest complexity and transactional difficulty - the city wants to lower the speed limit but technically it can't, so it's puts s*** in the middle of the road. Roads like Bryant Ave S north of Lake St. have humps, and I do have to admit it's absurd that road is technically a 30 mph limit. Going 30 on that road will get someone killed.

[RailBaronYarr]

Going 30 on any street has a 50% chance of killing an adult pedestrian (ok, 45%) and for children it's much higher.

[MNdible]

Careful with statistics.

I assume that you mean that, if a car hits a pedestrian when going 30mph, there is a 45% chance that the pedestrian will be killed, which is horrific, but completely different than what you said. Also, I assume that the statistic points to a car actually going 30mph at the time of impact, which if you think about it is only likely to happen if somebody bolts out into traffic, or somebody blows through a stop sign at full speed.

[Obviously, both of these things can and do happen, but changing the speed limit on a street won't stop them from happening.]

[PhilmerPhil]

Well, it looks like it's back in discussion: http://www.twincities.com/dakotacounty/ ... nts-debate

[RailBaronYarr]

Yes, obviously. I guess I thought it was obvious since millions of American pedestrians aren't dying at just the sight of 30 mph vehicles passing them by.

Yes, you are correct that those are the fatality rates based on speed at impact. I'll contend that the combination of people's poor reaction time and reality of how fast vehicles slow down make the difference between travel speed and impact speed on collisions very close. Also that a person bolting out or someone blowing through an intersection are not the only ways for impact at speed to happen. Texting while driving, a moment's indifference or lack of attention, and flat out swerving or careening off the street all can cause collisions at speed. With that said, car speeds on streets with people should give a reasonable shot for survival should a kid or adult bolt out in to the street. Changing the speed limit on the sign obviously doesn't work. Changing the street design does.

[bubzki2]

Well, I found the studies that I was looking for.

http://156.142.40.9/Weblink8Public/0/do ... age58.aspx (pages 42-59)

Looks like Plymouth's policy required 75% of local residents, of which they got only about 60% at the time. I called the city attorney, though, and he makes it sound like the moratorium (page 58) is basically toothless.

Interesting, also, is that the Farmington study indicates that "humps" slow you to about 20 mph, and "bumps" to about 5. These Plymouth humps slow you to about 5 mph and are nowhere near 12 ft. as Farmington defines humps.

[talindsay]

Heh, 5 mph. I had a 2004 Elantra GT that could take the old speed bumps on West River Road at 30 mph without scraping, thanks to some really stiff shocks. You could catch air sometimes. On my scooter I could catch air at 40 on the same bumps. Ironically, big heavy "tough" SUVs would have to slow to a near-stop to clear those same bumps without scraping.

Stupid (awesome?) stories aside though, there's a huge difference between speed bumps and speed humps. Speed bumps introduce a very real liability for the entity that puts them in since they can really mess up a vehicle even at low speeds, and are really an obstacle in a public roadway, which is not a good idea under any circumstance. Speed humps, on the other hand, when properly implemented can do a very good job of calming traffic and improving pedestrian safety without introducing any real risk of harm to vehicles. The ones on the East River parkway behind Coffman are surprisingly effective - which is kind of a waste since there's never much pedestrian traffic to benefit, though I like them when I'm running down there. A speed hump does require some real engineering to make it effective though - it has to be part of a complete street plan that considers all the various elements of multi-modal traffic on the street to be a good and useful tool. Simply sticking a long speed hump in the middle of a relatively high-speed road with poor pedestrian amenities will do nothing except annoy people and waste money.

[Tcmetro]

I've always felt that the speed humps in Minneapolis were quite effective and well thought out, in comparison to the speed humps and bumps that are in the nearby suburbs.

[MNdible]

I assume that Tom's carhorn plays Dixie when he flies off the speedbumps, and it it doesn't, I don't want to know.