IAM poll on increasing motorway speed limits

[kwackers]

Here's another way to look at it.

If 19 extra people are killed at an average age of (say) 40. Then they'll have been deprived of about 40 years of life.
If there are 20 million motorists, then each year whatever benefits they get will cost 20 minutes of someone else's life.

What will you spend your 20 minutes on?

[Jonty]

As a driver I'm in favour of variable speeds on motorways. When there is light traffic on the motorway I think 80mph is acceptable. My car cruises nicely at 80 and gives a good consumption at that speed in 6th gear.
Most of the time, however, 70 mph is IMO too fast because of the sheer volume of traffic. Many sections of motorway now have a 50 mph speed limit to cope with the volume of traffic (slowing it down to 50 increases throughput capacity).
Generally I do not think this is a matter for cyclists.
jonty

I bet I wouldnt call it good.
You know very well that it would be a lot better at 60mph. Wouldnt leave as much smog for the people behind to breathe either.

Seriously, it's about the same doing 80 mph in 6th gear as doing 60 in 4th or 5th - about 50mpg. Most of the time on motorways I drive about 65 mph because of the conditions.
jonty
Golf 2.0 GT TDI

[meic]

Have you ever thought about doing 60 mph in 6th gear?

Our larger Passat Estate does 57mpg overall, so cruising on a motorway it must be over 60mpg.
That is with an old inefficient motor that was a target for the environmental scrapage scheme!

[SilverBadge]

The TRL reckon (PPR397, "An evaluation of options for road safety beyond 2010", Sexton and Johnson, 2009) that increasing motorway speed limits to 80 mph (and enforcing them) would increase annual fatalities by 18, serious by 64 and slight by 363.

Then we would have pressure to raise limits for HGVs. And then dual-carriageway limits. And then single carriageway non-built-up roads.

A quick scan of its 100 pages doesn't reveal whether these are just motorway deaths. I would find it highly unlikely for an 80mph limit on motorways not to result in faster travel on other trunk roads. There is also the issue of speed intoxication - even if other limits aren't changed people will not realise how fast they are going and its inappropriateness. You only have to look at the EuroRAP accident data - once you have filtered out scofflaw bikers' favourite venues for premature suicide the most casualty-productive roads are those just off motorways, particularly the M62.

[pga]

What a shower we have in government - fighting wars to protect our fuel supplies and ignoring the threat of global warming, rather than introducing measures to reduce fuel use, eg by reduced speed limits and not increasing them - 55/60 mph on motorways and A roads, 30/40 mph on B roads and outside built up areas and 20mph in built up areas would be a start.

[Tonyf33]

On a motorway I'd hazard that isn't always the case, x driver at 60mph comes up behind a slower moving vehicle and pulls out not indicating into lane two maintaining their speed, cars behind have to brake suddenly or change lanes quickly to avoid possible collision.

there's two problems here. x doen't check that the overtaking lane is clear. following drivers haven't used observation skills to predict that x is gaining on the lorry and is likely to pull out.

i fail to see how if they're going faster the problems would simply disappear.

You've not read what was put previously then as this was a singular example to show that increased speed on a motorway for bad drivers didn't always mean a worse outcome. Thus, two bad drivers at differing speeds, the one driving slowest is actually causing more chance of conflict/incident due to that speed.
Even with following drivers not observing because the closing speed between those in lane 2 is less to that of the vehicle at 70 than that at 60 (so you have more time to react to the idiot overtaking with no signalling at 70 than 60) This dispells the statement made by Kwackers as being absolute, which I specifically said as you've quoted me that isn't always the case.

A bad driver at 60mph is safer than a bad driver at 70mph - that's the problem with speed.

In any case I never at any point said that any particular problem your hinting at would disappear, nor was I trying to intimate such. If you read what I said I disagreed that raising the motorway speed to 80 would increase the problems at the end of the slip road when exiting a motorway (due to the reasons I gave in my previous post)
I also said that it was the action of the driver that was more important than the speed itself more often than not but actual speed was relevant as well, hence I was not dismissing it completely. Something that Kwackers failed to understand from what I had written.
HTH

[SilverBadge]

You've not read what was put previously then as this was a singular example to show that increased speed on a motorway for bad drivers didn't always mean a worse outcome. Thus, two bad drivers at differing speeds, the one driving slowest is actually causing more chance of conflict/incident due to that speed.

Your example relies on there being an even slower driver present before a "situation" is even created. The faster example of the middle speed driver will have been closing down on the really slow vehicle more quickly, yet apparently this doesn't create any extra likelihood of misjudgement. It is a contrived example.

[Tonyf33]

You've not read what was put previously then as this was a singular example to show that increased speed on a motorway for bad drivers didn't always mean a worse outcome. Thus, two bad drivers at differing speeds, the one driving slowest is actually causing more chance of conflict/incident due to that speed.

Your example relies on there being an even slower driver present before a "situation" is even created. The faster example of the middle speed driver will have been closing down on the really slow vehicle more quickly, yet apparently this doesn't create any extra likelihood of misjudgement. It is a contrived example.

I didn't give the example of the speeds, Kwackers did, he said dangerous drivers at 60mph are more dangerous than that at 70mph, I gave a specific example to disprove that. Thus it was meant to be a contrived (but feasible) situation.

[kwackers]

I also said that it was the action of the driver that was more important than the speed itself more often than not but actual speed was relevant as well, hence I was not dismissing it completely. Something that Kwackers failed to understand from what I had written.
HTH

Not at all, I completely understand it.
But what I don't understand is why you think drivers would improve just because the speed limits increased? I've never seen any evidence that will be the case.
What has been shown time and time again in studies is that it's the difference in traffic speed that's the bigger issue, not the absolute speed. If everything on the motorway is doing 80mph then there wouldn't be an issue.
The issue is that increasing speeds also increases the disparity between the slower and faster traffic and that's where the problem is.

Driving standards are to my mind a fixed variable - that is there's no reason to assume that changing speed limits in either direction will have any affect whatsoever.

So your "contrived" example failed because it demonstrated an issue which comes around due the disparity in traffic speeds, - something that gets worse as speeds increase. Your crap driver pulling out at 60mph into 70mph traffic is easily as likely to be crap driver pulling out at 60mph into 80mph traffic.
Even if he sped up to say 70mph to match traffic speed increases he'd still be 10mph under the speed of the vehicle he pulled out on - except now both vehicles are travelling faster and with worse prognosis for any incidents.

I'm sure you've got a point in there somewhere - but I'd give up trying to defend your example and think of one that works.

[meic]

Also there are some of us out there who dont feel obliged to drive at the maximum speed limit, even on motorways.
60mph gives the optimum ratio of utility to performance so I will probably remain at 60mph when the majority rises from 80+mph to 90+mph when the speed limit increases. Although they will still slam on the brakes and come down to a bit slower than me every time they see a yellow square.

The speed differential may be a safety issue but if you are the slow driver in the scenario it generally means that you can hold a steady fuel-efficient speed for most of your journey, while the speedkings are bouncing from throttle to brake and getting just as overheated as their engines.

[swansonj]

Like, I sense, an increasing fraction of motorists, I drive at 60-65 mph on motorways through choice (that's my true speed, which corresponds to 65-70 mph indicated on the speedo) - or 55-60 if I'm in no particular hurry.

However: I also feel at least neutral if not positive about raising motorway speed limits to 80 mph. My reasoning is as follows. Most roads are shared between cars, motorbikes, cyclists and pedestrians. We fight and must continue to fight for the principle that on shared-use roads, car driver behaviour must be constrained by the presence of the other road users: the other road users have just as much right to the road as the cars do. On motorways, by contrast, the car drivers have the road to themselves; more vulnerable users are excluded. I feel that it is important to preserve this distinction: car drivers are not entitled to seek to exclude cyclists from ordinary roads, because they, the drivers, already have a dedicated network of roads all to themselves, called motorways. I think permitting drivers more liberties on their own dedicated space may be no bad thing from this perspective.

Of course, there has to be a limit somewhere, I'm not so libertarian as to want drivers to be allowed to go as fast as they want. And motorways may not include cyclists but they do include some car drivers who are relatively more vulnerable than others. But I have thought for a while that a simultaneous introduction of 20 mph in all residential roads and 80 mph on motorways could be a way of making those poor motorists feel less persecuted and therefore more willing to accept it, and could play quite well overall for cyclists. (Or even better: extend the concept of variable speed limits on motorways so they become 60 mph in the wet, 70 as a default, and 80 or even 90 mph on dry roads with traffic below a certain level.)

[Vorpal]

However: I also feel at least neutral if not positive about raising motorway speed limits to 80 mph. My reasoning is as follows. Most roads are shared between cars, motorbikes, cyclists and pedestrians. We fight and must continue to fight for the principle that on shared-use roads, car driver behaviour must be constrained by the presence of the other road users: the other road users have just as much right to the road as the cars do. On motorways, by contrast, the car drivers have the road to themselves; more vulnerable users are excluded. I feel that it is important to preserve this distinction: car drivers are not entitled to seek to exclude cyclists from ordinary roads, because they, the drivers, already have a dedicated network of roads all to themselves, called motorways. I think permitting drivers more liberties on their own dedicated space may be no bad thing from this perspective.

So, what about those newer/refurbished A roads where cyclists (and other slow moving or vulnerable road users) are increasingly excluded? They are motorways in all but name, shouldn't the speed limit be 80, there, as well?

[snibgo]

Yes, that's my worry.

I initially thought: I'm a cyclist, so why should I care what motorists do on their segregated roads? Maybe they'll love motorways so much they'll keep off our roads.

But a quick google found loads of people clamouring for raised speed limits all over the place.

"You can have 80 on motorways if we can have 20 in towns." Sounds interesting, but that isn't what Hammond is talking about. He is talking about, "80 on motorways and forget this 20 nonsense." (I paraphrase.)

[swansonj]

However: I also feel at least neutral if not positive about raising motorway speed limits to 80 mph. My reasoning is as follows. Most roads are shared between cars, motorbikes, cyclists and pedestrians. We fight and must continue to fight for the principle that on shared-use roads, car driver behaviour must be constrained by the presence of the other road users: the other road users have just as much right to the road as the cars do. On motorways, by contrast, the car drivers have the road to themselves; more vulnerable users are excluded. I feel that it is important to preserve this distinction: car drivers are not entitled to seek to exclude cyclists from ordinary roads, because they, the drivers, already have a dedicated network of roads all to themselves, called motorways. I think permitting drivers more liberties on their own dedicated space may be no bad thing from this perspective.

So, what about those newer/refurbished A roads where cyclists (and other slow moving or vulnerable road users) are increasingly excluded? They are motorways in all but name, shouldn't the speed limit be 80, there, as well?

I'm not pretending there are easy answers. I think roads should go in one of two directions. Either become a full-on cars-only road (either a formal motorway or an A road with cyclists etc excluded), or remain firmly a shared-use road, with lower speed limits and road design accommodating slower users (eg design of slip roads). But, if roads are converted to cars-only, there has to be acceptable alternative A to B provision for excluded road users. If that alternative provision could be relied on, I'd be fairly neutral* as to which way any given road went - whether it became a motorway or motorway-equivalent or not. Under the present culture, we all know that the alternative provision will be non-existent or rubbish, so we should usually try to insist on A roads remaining usable by cyclists in a vaguely safe manner.

*"fairly neutral", that is, as a cyclist. As someone concerned about the environment, which overlaps with (but is by no means the same thing as) being a cyclist, I of course think there are already too many roads and that car driving should not be encouraged further.