Hypermiling vs speed bumps
 

How do I negotiate speed bumps efficiently?

I know - take a route without them.

But what if I don't have an alternative? My neighborhood street has about 6 bumps over 300 meters, some of them quite big. Until now I would pulse, coast, engine brake, roll over the bump, pulse, coast, etc. Sometimes (if there is noone behind me) I pulse to a lower speed and then don't engine brake before the bump. When I can, I go closer to the edge which is lower.

Am I doing it right? Any better ideas?

speed bumps? what speed bumps? i ignore them, and replace my shocks and get an alignment every 2-3 years.
i hate doing that to the car but i will not let a sleeping policeman tell me how fast to go.

They're a pain.
They wreck your shock-absorbers - meaning your car becomes less safe far more quickly, anywhere else on the road.
They wreck your FE bij forcing a slow down even when its not needed.
They cause more fine dust (from braking , then accelerating again).
They cause excessive noise for the neighbours (suspension, braking, accelerating again)
Hence, they lead to far more pollution than necessary.

I expect we'll see the start of their removal within 5 to 10 years, when the minds of those in charge have finally changed ...

I just drive around them on my bike ;).

regards
Mech

Fortunately, speed bumps are very rare outside of parking lots on this side of the Atlantic. I try to hit them at the end of a glide, but I won't brake for them. They're no worse than potholes, which I take at speed as well.

If you drive fast enough, your sprung mass hardly has time to react and you barely feel the bumps. I can't imagine that 40lbs of unsprung mass flapping around puts much wear on the suspension.

Can you rent a heavy plow truck? BUMP - BUMP - BUMP - no more problems for Svietlana.

Heh, speedbumps at more than 30 in the Jeep can be interesting. You get slammed pretty hard, as being solid axle, it has a lot of unsprung weight. I slow down a bit, to around 20 - 30 mph, depending on the height and length of the bump. I know the suspension can take it, as it's usually pretty smooth if I judge it correctly, and it's a Jeep. However, the obnoxiously sharp (tallish, very short length) bumps in parking lots are usually a crawling affair, as they're too harsh to cross quickly.

I know a guy with a beat up 97 Saturn SL1 who just says "screw it" and takes them at 40+. I've seen him catch air that way :eek:, but at least he's not wasting gas (even though that's not his intent).

...where I work, they installed three (3) sets of them (!!!) at all of our entrance/exit gates at different spacings.

...they call them "traffic calming devices"...however, I definitely do NOT feel one-iota CALMER whenever I drive over them.

Take them at an angle and you can take them faster. Get left front over the hump before the right front starts up and things work out better. Doesn't work on the ones that are "wide". But the ones that are just a foot or so wide a approach angle will really make a difference. (For bikes approach at 90 angle. But car/truck approach at something less)

Political forces implemented them and political forces can take them away.

But this is like trying to get laws repealed. It's similar to writing something in stone (or graffiti?). Once it is done, it's much harder to get it undone.

Remember, it was probably your neighbors who thought it would be a good idea, petitioned for it and had it enacted - to reduce or eliminate the flow of traffic on "their" street.

Go petition your local legislators against the collective will of your neighbors. Good luck! :rolleyes:

Husqvarna Construction Products Husqvarna PG 3514

rent one of the like and execute a midnight op. Or do it during the day. Wear a vest and have a friend with a stop/slow sign. If you look official you should not receive any trouble.

Note: This suggestion is likely illegal and is made only for entertainment purposes.

The speed bumps are definitely there for safety, not FE, so slim chance of getting the neighbors to remove them. Especially since I also don't want to step out of my entrance gate in front of a car that is trying to break the sound barrier.
Without speed bumps: most cars go 40-50 km/h, but many (25%) go as fast as 90 km/h.
With speed bumps: most cars go 30-40 km/h, while about 10% floor it and accelerate to 60 km/h and suddenly brake hard, then again and again.
Mind you, this is a small residential street with intersections every 100m.

That reminds me of a joke: What kind of car can take a 12 inch curb at 45 mph? Someone else's.

There was a post here somewhere about an active speed bump that would lower if the car was going slow enough. I can't find it at the moment.

Wish my street was peppered with monstrous speed bumps.

http://ecomodder.com/forum/showthrea...ust-10734.html

This reminds me of the "active suspensions" out there that could pull back just as fast as the speed bump rises, and you could go over it at 90kph and not feel a thing.

Edit: Here those are. Sixty seconds into this video: http://www.youtube.com/watch?v=eSi6J-QK1lw

I have 5 BIG round-top bumps on my final approach to work, and departure in the evening. I take them at 15 mph (parking lot) speed, so I don't have to do one last pulse. Taking them at street speeds, though, I don't know.

The Odyssey van, on the other hand, gets all out of sorts on the same bumps. Wheel hop, skittering sideways, wallowing. And I chose the Ody because it's one of the best-handling of the minivan bunch. It's still a tiptoeing hippo.

What is the world's fastest production road car ?
Any hire car.

We have speed humps on our street and I'm happy with them otherwise we get the usual morons doing 50 in a 30 zone. We still get the occasional moron in a 4x4 doing the same. They are designed to brake springs at over 40 but be smooth at 20.

I match my speed to the hump design so about 20. As I crest the first one I pulse to the next one and arrive at about, or just under 20 and go over and repeat. If nobody is behind I can pulse and take two of them in one glide. If I'm being tailgated (X-5 driver usually) then I glide for more than two.

My real limitation for P&G in my street is parked cars and everyone else playing chicken passing them. I had this on Friday - a black cab no less deciding to pull out onto my side to pass a line of cars despite me coming the other way with my lights on. I think he expected me to go ont he pavement to let him past.

So it was time to stop, put the handbrake (aka parking brake) on and wait. After all he's paid by the mile behind the wheel, I'm on my way home from work :D

...I *knew* those mexican "jumping" cars would catch-on eventually (ha,ha)!

There is an "active" suspension system for negotiating speed bumps and potholes, but there are a few gems out there that require hyperactive suspension.

My front tires actually spin a bit and chirp as they hit the ground if I go over a bump too fast. It has a lot of torque on idle.

I would blow the horn on and off for about 5 seconds when I slowed for the bumps they might recommend that the bumps be removed after hearing all the protest. I understand people wanting to do something to prevent speeders from zipping down the street at unsafe speeds but to hold all drivers hostage because of of a few is unamerican.
Rather than speed bumps they should set up a camera radar system and nail speeders all the way to the bank. Some roads the speed limit is not accurate others the speed is too high. For instance there is a road that has a speed of 35mph the road is straight 3 miles long light traffic people are going to drive down that road around 55 I do 35 but they act like I am a weenie for doing the speed limit. Other locations have 65 mph homes close proximity to the road heavy traffic and hardly any room to accelerate to the speed limit.

I would get your license and... who knows... you would soon have a reason to stop doing that.

That camera should be equipped with a microphone to record instances of motorists disturbing the peace with unnecessary horn blastings. :rolleyes:

Using your horn within city limits is not legal here, and wouldn't score you points with the neighbors even if it was. Nobody would invest in a speed radar on a residential street since the traffic is too low. The local gov't would put out $$$ to catch 3-5 speeders per day for the first week, and after the first week the radar would look like this:

http://ecomodder.com/forum/attachmen...1&d=1280899937

Really?!! Wow. Around here, you'd think the law was that you MUST use it! :p

I wish we had a law about the trains using their horns in the city, though. Working half a block from the track = LOUD!

There are laws against unnecessary horn use, but I couldn't imagine them being enforced unless you're a jackass about it.

Being unamerican is my existance, mainly because I am not one. :p

TBH though equating your right to go at any speed as 'freedom' vs safety seems a little, well, dumb. Also stop outside my house and 'toot' in protest and you may find some products of the LBC coming your way. :cool:

Lets get this straight though. I am not a speed nazi, I think going 90 on a clear motorway with little traffic is fine, 60 on an open country road is fine too. But 40+ down my street, and that is what the morons did before the humps, is dangerous - end of argument, not negotiable.

If you are that upset, take a different route.

Welcome to my country.

We have speed cameras everywhere. Not just instant ones but average speed ones too - they read your plate and point a and then point b and calculate how fast you went between the two.

Does this all work ?

No.

For a start people learn where they are and slow down. Sat navs have them on their maps and beep when needed. Even radar detectors detect passive ones when they bounce off other cars.

And a lot of the cars they do catch are not registered correctly, so they can't nab the owner anyway.

And in fact this makes it worse. If (like me) you legally register and insure you car (a requirement here) then you get speeding fines. Don't bother to register or insure your car and get away with it.

So not exactly fair is it ?

So humps work for me.

...as I recall, Memphis, Tennessee, has "Anti-Noise" Ordinances on horn usage, or they did back in the 1960's!

I liked to kill the engine once on my street and coast to my house, bouncing into the driveway silently until I broke both front shock mounts from the unibody! A lil welding and its good as used...

I have two obsevations that may help, I have found that there is an optimum speed for railway tracks or speed bumps, neather to fast or to slow for the suspension. You can expierament... to find the smoothest travers of the bumps. I found that 20km/hr was the best. The other observation is that if I go across the bumps at a slite angle so that each wheel goes over the bump alone, the ride is smoother. I hope this helps.

^ yes.

That optimum speed depends very much on the car, though. On my two Hondas, a civic and an odyssey, the best speed is respectively 15 mph and 8 mph.

Lighter wheels help too - unsprung weight has a hard time going over bumps smoothly.

Where I grew up they're everywhere and alot of them are way too big and solid to attempt going over without coming to a complete crawl. I made that mistake once... I hit one at 35kph and all my friends smashed their heads against the ceiling of the car... I wasn't too popular...

Where my Dad lives now... His suburb is known as humpville and he lives on a steep street covered in speed bumps so you can't gain or make use of any momentum at the bottom of the street to help you get part way up the hill. Constantly wasting gas and revs just to get home everytime. Most of the time they're in places where there are no/very few alternative routes!! Very frustrating. I wish I could give advice but it sounds like you're doing everything as best as possible.
I think in New Zealand speed bumps are a whole lot more serious than the smooth raised strips and bumps that I drive over here in Canada!!

The problem with the speedbumps is the wear on your unibody. It's not just an upward force. The tire hitting the bump causes the suspension to push rearward on the unibody. Even worse if you have a coil sprung solid axle up front like me. The control arm angles cause the tire to be pushed forward into bumps, increasing the unmitigated force getting to the frame.

I second that. Speed bumps (particularly tall, harsh ones) are the only time I don't love my solid front axle.

try my dd a 81 solid axle toyota, with leaf springs all the way around. also no a/c or powersteering.
urg at speed bumps and rail road crossings.

Since they are only 50 meters apart will traffic and speed allow you pulse 2 at a time? Pulse to the first and continue until the next and once over that pulse again?

Have you used your SG to try different techniques to see what works best?