60 MPH Limit on Motorways

[EssexExile]

Pollution levels are made worse by erratic speed, acceleration and braking. A constant speed is more efficient and less polluting, that's the point of managed motorways.

[Harvey1512]

The reduced limit may also help the traffic flow better. Consistent moving cars pollute less than stop start cars, cars that are braking and then accelerating.

There are a couple of stretches near to me which have 50mph limits and they work pretty well, better than the previous national speed limits.

Edit, sorry I hadn't seen the previous post which covers my point.

[Dash300]

Originally Posted by Dippydog

There have been several fuel "crises" the last I think was '74 or 5 when it was mooted that fuel rationing was a possibility-I still have the [unused as the rationing never took place]ration book issued for the MkIII Zephyr I owned at the time.I'd have thought pollution levels more a by product of traffic volume rather than speed?

1973 fuel crisis with Saudis messing about with supply. I still have my fuel vouchers issued in relation to vehicle logbooks. Lots of sheds went boom as people stockpiled fuel! 'And you tell the youngsters today and they just don't believe you but we were 'appy!

[GMcL]

There is an argument that recent events have failed to reduce polution:
https://eandt.theiet.org/content/art...d-study-finds/

You can either be told what to believe or you can do your own research...

[MROffroad]

As a HGV driver slowing people down will force trucks to slow... this will push them out their efficiency zone.... use more fuel and more smog into air. 11mpg on a run and 5mpg working hard is not great

[GMcL]

Shhh! Never mind facts, you are one of hundreds of trucks it will all even out in the mash.

[Harvey1512]

Originally Posted by MROffroad

As a HGV driver slowing people down will force trucks to slow... this will push them out their efficiency zone.... use more fuel and more smog into air. 11mpg on a run and 5mpg working hard is not great

Why would it force trucks to slow? If cars are moving smoothly and evenly at 60mph then surely you can carry on driving at your legal limit smoothly as well? Cars doing 80 then breaking, the concertina effect, will affect you much more I would have thought.

[green van man]

M4 around Port Talbot has had 50 mph limit for years, now extended by about 5 miles to control polution.

Irony is, the steel works pump out far more from their blast furnaces than the traffic passing does. Hay How, set the cruse to 50 and bumble through. Average speed cameras have replaced the single speed camera so if you don't want to pay you know what to do..

The thing with hgv or limited vehicles is loss of momentum, while my 5 ton limited van will pick up again quite well for what it is try that with 42 ton behind you. Approaching a hill you are trying to biuld momentum to carry you up and you will be limited to 56 mph, the car in front is doing 60, but when it hits the hill it too is lacking momentum, if it's a 200hp volvo driver puts his foot down and away he goes, if it's a clapped out Nissan micra driver puts his foot down and very little happens except more smoke comes out the back end, by which time the the limited vehicle is having to back off, momentum is lost and it is now a hard slog through the gears to get to the top. My limited vehicle will exceed it's set limit downhill with foot off the throttle, the moment you put your foot down engine braking comes into play and it holds you back.

Try it with older cruse control systems where they are braking down the hill to keep the set speed and then driving hard up the other side trying to maintain the set speed. Driver would back off down hill, letting the car run faster then use that potentential energy to assist the climb.

Paul.

[M4ss4]

The 60 limit to help pollution had been present between junc 27 - 29 on the M1 at various times over the last few years. It seems to not be a thing at the moment. It wasn't really a big deal but did feel frustrating when the motorway was somewhat empty.

From what I read yesterday the trial for the M1 will be junction 34 which is after I leave the motorway so won't affect me now. With that particular stretch being a large bridge it always feels somewhat exposed in poor weather (common for Sheffield haha) so always tend to hold back there anyway. Will be interesting to see what the results in pollution reduction are really.

[alanin53]

1973 fuel crisis with Saudis messing about with supply. I still have my fuel vouchers issued in relation to vehicle logbooks. Lots of sheds went boom as people stockpiled fuel! 'And you tell the youngsters today and they just don't believe you but we were 'appy!

Shed? Luxury! We used to have to keep our fuel in an 'ole at t'bottom of t'garden.