Truck speed limiters

**EnglishPaul** · 10-14-2007, 02:21 PM

I was wondering, is it just Europe that has a requirement for Trucks above 3.5t to be speed limited, and if not where and to what speed?
Also, what are the speed limits of trucks in your country?
And finally, do you think that speed limiting trucks is as stupid as I think it is?

**kodi** · 10-14-2007, 02:34 PM

Trucks in Australia are speed limited to 100kph
It is a good idea as it stops the Cowboys in the Trucking industry killing themselves and innocent families
Trouble is trying to implement it as most trucks can do about 110kph even when speed limited
The old Scania I used to drive could do about 120kph simply by removing a fuse that controlled the blinkers and speed limiter

**EnglishPaul** · 10-14-2007, 03:19 PM

Thanks Kodi.
I am of the other opinion, however.
What happens in the UK is that trucks are all limited to 56mph, and so overtaking is dependent upon what bias the limiter is set at (and they seem to vary quite widely) and what the gradient is.
In my opinion what happens is this: on our 3 lane motorways, of which trucks are banned from lane 3, when 1 truck overtakes another it takes a long time (due to the small differential between limiters). While this overtaking is going on, cars (traveling on a motorway at 70mph by law (or 85mph in reality)) have a huge speed differential with the overtaking trucks. Soon cars get stuck behind the trucks and in desperation pull out in to lane 3 at about 60mph which is still 25mph below the norm. Existing cars in lane 3 then need to brake, and later cars either brake too much and set a rarefaction down the motorway that causes a jam, or brake too little and go into the back of another car.
Thus the motorways work less effectively as cars get jammed up.
Without speed limiters, speed differentials could be higher, overtaking of trucks would thus be shorter and the motorway would see less holdups.
Furthermore, I notice that since I had a speed limited fitted on the 7.5t truck I drive since christmas (change in the law), I now drive far closer to other trucks to minimise the inconvenience to others when overtaking. Such small gaps when following trucks can't be safe- especially as you can't see over a truck to the road ahead. So my driving has become less safe.
Finally, in vehicles with cruse control you don't even need to operate the accelerator, and so for long motorway journeys all you are doing is steering. And if that is not a recipe to fall asleep or not concentrate, I don't know what is.

I am glad that with limiters, the operators can not force drivers to brake the speed limits. But it doesn't work that way. Instead the temptation is (for people like me who do not know how to defeat the limiter) to make up time by diving at 56mph on all roads whether they be past a school or not. On balance I can't see limiters are a good thing.
[Although I do concede that the limit of 56mph is better for fuel economy and therefore better for the environment. But what speeds trucks should be aloud to drive at is a new thread.]

10-14-2007, 02:21 PM	#1 (permalink)
EnglishPaul Still no avatar Join Date: Sep 2007 Location: Sheffield Posts: 989 OS: XP SP2	Truck speed limiters I was wondering, is it just Europe that has a requirement for Trucks above 3.5t to be speed limited, and if not where and to what speed? Also, what are the speed limits of trucks in your country? And finally, do you think that speed limiting trucks is as stupid as I think it is?

10-14-2007, 02:34 PM	#2 (permalink)
kodi Moderator Hardware Team Join Date: Jun 2004 Location: Sydney Australia Posts: 6,575 OS: Windows Vista Ultimate, XP Professional My System	Re: Truck speed limiters Trucks in Australia are speed limited to 100kph It is a good idea as it stops the Cowboys in the Trucking industry killing themselves and innocent families Trouble is trying to implement it as most trucks can do about 110kph even when speed limited The old Scania I used to drive could do about 120kph simply by removing a fuse that controlled the blinkers and speed limiter __________________ Brian

10-14-2007, 03:19 PM	#3 (permalink)
EnglishPaul Still no avatar Join Date: Sep 2007 Location: Sheffield Posts: 989 OS: XP SP2	Re: Truck speed limiters Thanks Kodi. I am of the other opinion, however. What happens in the UK is that trucks are all limited to 56mph, and so overtaking is dependent upon what bias the limiter is set at (and they seem to vary quite widely) and what the gradient is. In my opinion what happens is this: on our 3 lane motorways, of which trucks are banned from lane 3, when 1 truck overtakes another it takes a long time (due to the small differential between limiters). While this overtaking is going on, cars (traveling on a motorway at 70mph by law (or 85mph in reality)) have a huge speed differential with the overtaking trucks. Soon cars get stuck behind the trucks and in desperation pull out in to lane 3 at about 60mph which is still 25mph below the norm. Existing cars in lane 3 then need to brake, and later cars either brake too much and set a rarefaction down the motorway that causes a jam, or brake too little and go into the back of another car. Thus the motorways work less effectively as cars get jammed up. Without speed limiters, speed differentials could be higher, overtaking of trucks would thus be shorter and the motorway would see less holdups. Furthermore, I notice that since I had a speed limited fitted on the 7.5t truck I drive since christmas (change in the law), I now drive far closer to other trucks to minimise the inconvenience to others when overtaking. Such small gaps when following trucks can't be safe- especially as you can't see over a truck to the road ahead. So my driving has become less safe. Finally, in vehicles with cruse control you don't even need to operate the accelerator, and so for long motorway journeys all you are doing is steering. And if that is not a recipe to fall asleep or not concentrate, I don't know what is. I am glad that with limiters, the operators can not force drivers to brake the speed limits. But it doesn't work that way. Instead the temptation is (for people like me who do not know how to defeat the limiter) to make up time by diving at 56mph on all roads whether they be past a school or not. On balance I can't see limiters are a good thing. [Although I do concede that the limit of 56mph is better for fuel economy and therefore better for the environment. But what speeds trucks should be aloud to drive at is a new thread.]