"Smart" motorways...a query

[miami]

My dear old dad always used to ignore the overhead signs (speed limits etc, this was before the Red X was invented!) - he said the people in the control room set them and then forgot to turn them off. To be fair he was right, you'd often see a 50 limit saying ACCIDENT AHEAD but there was no such accident.

Yes, those limits are advisory (no red circle), and often ignorable.

The Red X has been around since 1989

 

[jon0844]

But you must comply with the red ring ones on the gantries at 3am on a totally empty road. Happened far too often, making me wonder if it was some sick joke at a nearby control centre!

 

[EssexGonzo]

No it doesn't, capacity is determined by all lanes, once offside lanes start becoming saturated, the lanes to the nearside start getting busier - peak flow comes at a lower speed than the national speed limit, the actual figure will depend a lot on driver gap acceptance, the proportion of large vehicles, geography, weather, glare from sunlight etc, but would be somewhere in the 30-40mph range.

Fair enough, the capacity is always there but as most cars will not "undertake" i.e. utilise the unused capacity in lanes one and two, you get a lot of unnecessary bunching in the outer lanes.

Is that not because of the stupidly large number of trucks in lane 1, and the occasional truck in lane 2 overtaking someone with a speed difference of about 2mph at most. When I drove up to Nottingham from London in mid January, I spent a lot of time in Lanes 3 & 4 simply because there was rarely a break in the traffic in Lane 2 worth going into.

I can see the scenario, but this doesn't occur anywhere near as much as 50% of the time.

"There's no point moving in as I'll need to pull out again in a mile's time" is not a valid argument for staying in the outer lanes when the motorway is busy. In France, most autoroutes are 2 lanes and cars will pull in right away to let traffic behind past. They're also able to easily join the outside lane due to the non-defensive mentality of more French drivers. The muppets on French motorways tend to be the Brits and the Belgians!

In the UK we hate letting cars past even if they're obviously going to disappear into the distance. Also, the car passing will often not execute a passing manoeuvre cleanly, leading to blocking in which I guess leads to the insecurity of those staying in outer lanes. And if, with our warrior-like mentality in our cars, we've already conquered the outside lane, we're certainly not going to let anyone else out in front of us!

Our roads are made less efficient by our psychologically-driven behaviour.

 

[Pakenhamtrain]

Sometimes the blue signs denoting the times of operation aren't very obvious, and if you miss them you probably assume the bus lane is 24/7 and using it would risk a penalty.

Ours are just white signs:
https://goo.gl/maps/9PEBoW3NNou
https://goo.gl/maps/XgitbnJhmjP2

In the UK we hate letting cars past even if they're obviously going to disappear into the distance. Also, the car passing will often not execute a passing manoeuvre cleanly, leading to blocking in which I guess leads to the insecurity of those staying in outer lanes. And if, with our warrior-like mentality in our cars, we've already conquered the outside lane, we're certainly not going to let anyone else out in front of us!

Try driving on some of our country roads. It' one lane each way with overtaking lanes every few kms along the road but if it's the dotted line you can overtake on the wrong side of the road if nothing is coming the other way.
You have drivers who end up doing 85-90km on the single lane bit with a massive line of cars behind them. Arrive at the overtaking lane they somehow find the extra power to get the car up to 100-110.

 

[miami]

Ours are just white signs:
https://goo.gl/maps/9PEBoW3NNou
https://goo.gl/maps/XgitbnJhmjP2




Try driving on some of our country roads. It' one lane each way with overtaking lanes every few kms along the road but if it's the dotted line you can overtake on the wrong side of the road if nothing is coming the other way.
You have drivers who end up doing 85-90km on the single lane bit with a massive line of cars behind them. Arrive at the overtaking lane they somehow find the extra power to get the car up to 100-110.

Same in the UK. You also get stuck behind lorries doing 30mph on a 60, which is fine. Unfortunately behind the lorry are 3 cars who refuse to overtake. You reach the first overtaking point, you don't overtake all 4 vehicles as that would be rude, you wait for them to overtake. They don't.

You reach the second point, but there's not room to overtake 4 vehicles, so you overtake 2 of them, you get flashed at.

You reach the third one and finally knock off the lorry, by now you've spent 10 minutes doing 5 miles where you should have taken 6 had the car drivers overtaken.

 

[jon0844]

In France, most autoroutes are 2 lanes and cars will pull in right away to let traffic behind past.

And especially in Germany on the autobahns, where cars could be doing 200mph!

There isn't the carnage because there's a respect for other motorists. The driver doing 70mph in lane one is aware of cars potentially doing 200, and the driver doing 200mph respects the car driver doing 70 because they'll only be in lane 2 to overtake a caravan/lorry.

What's more, the driver doing 200 is already aware that if a car is in lane one that's gaining on a lorry ahead (which likely isn't allowed in lane 2 at all during the day) it will want to pull out, so the driver slows and knows s/he can speed up after.

It all works well the vast majority of the time. Can anyone imagine that here? I mean, people straddle two lanes approaching road works to stop people using all available road space to merge in turn! It's so much about 'hey, you're not getting by me' that it's unreal.

Smart motorways work well when motorways are really busy, but a lot of the time you'll see motorways looking like you'd think a photo of it had been mirrored!

 

[Bletchleyite]

Sort-of in the case of the Autobahnen - they don't have a great safety record.

 

[exile]

Same in the UK. You also get stuck behind lorries doing 30mph on a 60, which is fine. Unfortunately behind the lorry are 3 cars who refuse to overtake. You reach the first overtaking point, you don't overtake all 4 vehicles as that would be rude, you wait for them to overtake. They don't.

You reach the second point, but there's not room to overtake 4 vehicles, so you overtake 2 of them, you get flashed at.

You reach the third one and finally knock off the lorry, by now you've spent 10 minutes doing 5 miles where you should have taken 6 had the car drivers overtaken.

Or you could just chill out and get to your destination 2 minutes later.

 

[miami]

Or you could just chill out and get to your destination 2 minutes later.

4 minutes later on a 5 mile stretch, but keep it going for 15 miles and the entire trip takes 50% longer than it should take.

How much money did the taxpayer put into the WCML to save 10% on journey times?

 

[radamfi]

4 minutes later on a 5 mile stretch, but keep it going for 15 miles and the entire trip takes 50% longer than it should take.

What is your solution?

I think it is reasonable to accept that on single carriageway roads it is quite likely that your average speed will be 30 mph or less. If a certain road is considered sufficiently important that traffic must move faster than that, then you need regular overtaking sections, an extra lane or dualling, and that would have to be justified under the usual appraisal process.

In the Netherlands they have dual carriageway roads with one lane in each direction most of the way, so overtaking is impossible. They do widen out into two lanes periodically to enable overtaking to take place.

 

[Robertj21a]

4 minutes later on a 5 mile stretch, but keep it going for 15 miles and the entire trip takes 50% longer than it should take.

How much money did the taxpayer put into the WCML to save 10% on journey times?

I think I'd much rather get there safely than save a few minutes. It's not a race !

 

[miami]

I think I'd much rather get there safely than save a few minutes. It's not a race !

However when there are clear places to overtake and people don't, it is rather annoying. Just like the people who slow down during winding roads.

It's not a race, that doesn't mean we should drive at 20mph everywhere.

 

[pdq]

However when there are clear places to overtake and people don't, it is rather annoying. Just like the people who slow down during winding roads.

It's not a race, that doesn't mean we should drive at 20mph everywhere.

Car performance can be a barrier to safe overtaking. I would describe myself as an experienced, confident driver (and IAM member). I have recently been driving my parents' 2003 1.25 Fiesta and it feels very slow compared to my own car - a 2015 1.4tsi Octavia. In the Fiesta I simply wouldn't feel confident in making the overtaking manoeuvre you describe without a lot of clear road and excellent visibility.

 

[Robertj21a]

However when there are clear places to overtake and people don't, it is rather annoying. Just like the people who slow down during winding roads.

It's not a race, that doesn't mean we should drive at 20mph everywhere.

Perhaps they simply don't want to overtake. If the cars behind are quite happy at that speed then they'll stay there (whether that suits you, or not). Speed limits are the maximum permitted, not, as many seem to believe, a figure that you have to achieve.

 

[90019]

However when there are clear places to overtake and people don't, it is rather annoying.

I don't buy in to this thing of overtaking being rude, or having to queue to overtake. If there's a gap where I can safely overtake and someone else doesn't use it, then I'll take that opportunity.
By the same token, if someone wants to go faster than me, and there's an opportunity for them to pass, then I'll indicate left and let them go, if necessary slowing down a little to let them pass safely.

 

[edwin_m]

Overtaking on single carriageways is probably the most dangerous driving manoeuvre, and ironically with fewer and fewer opportunities to practise it probably gets more dangerous rather than less.

When there is a queue behind a slow vehicle on a single carriageway, if a vehicle other than the first in the queue chooses to overtake then they run the risk of being side-swiped by someone further up the queue who belatedly decides to overtake but is concentrating so much on looking for a gap from the opposite direction that they forget to look in the mirror before pulling out.

However I think we came into this particular bit of discussion via short overtaking sections of dual carriageway, where this particular issue doesn't arise so much.