Speed hump guidance please

[WestyNottm]

I live within a private estate (if it was America it would be called a gated community!) and a speed hump is going to be installed on the main driveway.

 

To avoid my new Westfield (2013 Sport 2000) getting marooned forever in my garage, I wonder if anyone has any advice on optimum dimensions for these things - or do I need to make my own ramp to get over it?

 

I have just found that a chassis member of my car (I have a 20mm lowered floor) just catches the electric gate stop that is secured in the middle of the drive when I have a passenger so I have learned to avoid that.

 

Thanks in advance.

[peterg]

There is a recommended maximum height (from memory) of 100mm for public roads - you should be able to Google for it - but on a private estate (and therefore possibly not an adopted road) there probably won't be any regulations so it'll be up to the developer/contractor....

[Rhett Turner - Black Country AO]

From experience different speed regulation humps have different effects on my Westfield. I would split them into thee main types,

• the good old fashioned hump, these are the original and sometimes plastic bolted down sort, these are not Westfield friendly and require a slow approach especially with the front wheels. I find I have to wait for the suspesion to settle once the front wheels have gone over the hump or sometimes the car grounds. A real pain. 
• the speed table, these are the sort that sit in the middle of the lane and in most normal cars don't cause any issue if approached with care. The trouble I have found with the Westfield is that 9 out of 10 are ok but every so often 1 has slightly different dimensions and the car will ground.  I end up takeing these very easy with the one wheel on one whell off aproach.
• the elongated hump, these are the sort where you drive up go along a little bit and then come back down, generally I have found these don't cause any more issue to a Westfield than a normal car.

If it's a private estate could you lobby for the elongated hump as this should not be an issue, ideally the length needs to be at least the same as your wheel base or as near as possible.

[TAFKARM]

• the good old fashioned hump, these are the original and sometimes plastic bolted down sort, these are not Westfield friendly and require a slow approach especially with the front wheels. I find I have to wait for the suspesion to settle once the front wheels have gone over the hump or sometimes the car grounds. A real pain.

 

If you take these diagonally they are usually much friendlier. 

[jonjh1964]

When I first got on the road I found the chassis hoop around the gearbox and the seat mount bolts were the causes of bottoming out.  The chassis hoop on speed bumps and the seat bolt mounts on speed humps and two up/full fuel on bumpy roads.  The worst cause was the transition between my garage and the slope on my drive which I had to take a diamond disc cutter to. It might be worth measuring the size of the gate stop and then measuring the chassis hoop and the floor pan heights with your typical driving load.

 

The things I did were to 1) reset the ride height ballasted with driver and passenger weight, an extra 80 kgs (passenger & fuel) over the original setup, and 2) cut the seat bolts down to only leave 2 threads clear, about 6mm off each.

 

Finally, I follow the advice above by Rhett and Russ and take speed bumps cautiously.  I've now driven about 3k miles, including 600 miles last weekend to Belgium, and can't remember any recent contact.

[WestyNottm]

Thanks all for the sound advice so far. I suspect the chassis hoop around the gearbox was the cause of the contact with the gate stop as I deliberately decided to centre the car over it (mistake), I'll check when I get home as no doubt there will be contact marks on it. As advised by Jon, I'll also take a look at the seat bolts and cut down if necessary.

 

In the short time I have had the car on the road, I have very deliberately driven slowly through the estate as I thought the loud exhaust noise would make my neighbours think I was driving faster than I really was!

 

I like the point made by Rhett about the crown of the hump = wheelbase length as I can see that would be the safest method. I just hope I can make representations without my neighbours thinking I want to go faster than would be sensible.

 

Also I remember doing an off-road trial in a 4x4 and learning the merits of driving diagonally over obstacles so thanks for the reminder Russ.

[XTR2Turbo]

I think I would push back against the installation of speed hump.

 

If one must be installed I would go for the very low but severe hard plastic type that you sometimes get in carparks.

 

You will never bottom out on them as only about 50mm high and all cars need to slow down equally for them.

 

If you get the large mound humps installed normal cars and especially 4x4s will bounce over them as if not there but you may bottom out in the Westfield.

[SootySport]

As you already know, there is no restriction on a private estate so I suggest you go to the residents meeting and find out how high the humps will be. You can also let them know how much clearance you need for your Westfield. 

[WestyNottm]

As you already know, there is no restriction on a private estate so I suggest you go to the residents meeting and find out how high the humps will be. You can also let them know how much clearance you need for your Westfield. 

That is exactly what I will do. I've had a look under the car and the gate stop I mentioned catching previously was obviously caught by the gearbox hoop and is a couple of inches off centre so the exact middle is even lower.

 

I will figure a way to measure the ground clearance with one and two up and make representations.

[User0083]

I'm with Rhett,

Although I do take every speed bump diagonally, slowly and I find that this works on all but the nasty traditional ones (like a row of bricks across the road). However I do not have a lowered floor.

I put left wheel as close to curb as I can, 3/4 turn to the right, middle of speed bump turn and a half to the left. I've found only skinny ramps catch at times... Unless I've given a fat nurse a lift home!!!

[Uisdean]

Preformed humps now tend to be 65mm or 76mm high. These can be flat topped or rounded. When they are used as raised crossing points for pedestrians they can be up to 100mm high to match kerb heights. The main problem is often the width of the hump as the shorter ones allow the car to straddle the hump and this is when the clearance becomes critical.

 

A good advice document is issued by DfT - just google search LTN1/07 for the document which covers all forms of traffic claming that can be used on public roads. This may help to get humps lowered if you find they exceed the heights shown in this guidance.

 

Hope this helps

[Marcus Barlow - Show and Events Co-ordinator]

This is my car (V8 sump and roll hoop) on a standard UK speed bump :-/

 

[Westie66]

On a few near to me I take to the pavement, sometimes there is no alternative

[BillyPee]

You can avoid the problem altogether by moving house or getting rid of the Westy 

 

Assuming you do not find either of those outs attractive, it seems sensible to make your concerns known to whoever is running your private estate. You might not stop the bump being fitted but they are likely to see the benefit of a bump that conforms to UK legislation (even if it doesn't apply in a private setting). Point out that it will mitigate their exposure to claims for damages to vehicles (if the hump is not "legal").

[pickmaster Andy Lowe]

You can avoid the problem altogether by moving house or getting rid of the Westy

Assuming you do not find either of those outs attractive, it seems sensible to make your concerns known to whoever is running your private estate. You might not stop the bump being fitted but they are likely to see the benefit of a bump that conforms to UK legislation (even if it doesn't apply in a private setting). Point out that it will mitigate their exposure to claims for damages to vehicles (if the hump is not "legal").

I agree there are regulations on height and type of hump and all new ones need to comply or they are blocking the public highway (but not sure about a gated community)?? As no public access in theory

If I was to move house I would not live down a road with humps as it would drive me mad slowing down to pass over them every single time I pop to shops, school run, work

I think it knocks £20k off house prices in an area with bumps and makes the property's less desirable as you now think its got a speed issue!!!!