UK motorways have traditionally have a "hard shoulder" for emergency use. To be able to break down and be out of the flow of traffic (moving at 70mph) keeps passengers and property safe.
The "Smart Motorway" has signs to turn this refuge into a full speed lane, leaving a couple of feet for the breakdown area.
I never understood how this could be approved by any Minister who wanted to retain their position, but I guess saving money on new road lanes is more important than the lives of the voters and their families.
Smart Motorways also try to slow traffic on approach to a bottleneck to ease the arrival of congestion before it brings the road to a standstill. In practice, drivers ignore the signs unless they have a speed camera attached to them, making the investment in the technology mostly useless.
Good riddance to this dangerous idea. Don't revisit it while cars have organic drivers.
From the BBC News article on smart motorways being scrapped, smart motorways can fall in to three categories:
* controlled, which have a permanent hard shoulder, but use technology such as variable speed limits to adjust traffic flows
* dynamic, where the hard shoulder can be opened up at peak times and used as an extra lane; when this happens, the speed limit is reduced to 60mph
* all-lane running, where the hard shoulder has been permanently removed to provide an extra lane; emergency refuge areas are provided at regular intervals for cars that get into trouble
IMO there shouldn't be any objections to "controlled" smart motorways. All lane running is idiotic; dynamic running is OK but I would say that the speed limit needs to be lowered from 60 mph.
As an aside: British drivers have terrible lane discipline on motorways ("middle lane hogging"), which eats up road capacity for no good reason. There's plenty of variable message signs on motorways - they should display "Keep left unless overtaking" if there's no other message to be displayed.
From daily experience of 10 miles of the M25, the all-lane-running has had a broken-down car in a live lane (i.e. the lane is not closed with a red X) about twice a year for me.
Also there are vague electronic signs saying "reports of obstruction", "report of blocked lane" or "reports of pedestrians" with no further actions (like a lane closure) maybe twice a week. There very rarely actually is an obstruction to be seen in the end, so the signs get ignored, even when there is an actually dangerous hazard like a car in the middle of a lane.
> British drivers have terrible lane discipline on motorways
They certainly do. They even made it illegal a few years ago, but it's virtually never enforced. For a start, there aren't very many road police to enforce it.
A small but significant number of people also completely disregard the red X markers and zoom down closed lanes towards, presumably since they don't usually do the red X for fun, a broken down vehicle or accident. This is very much illegal (though it's only a £100 fine), but again seems not to be enforced sufficiently to prevent it.
I’ll provide an unpopular opinion. People who rigidly stick to the “furthest left lane at all possible moments” are far more dangerous than middle lane hoggers. I witness many, usually white vans, who seem to want to enforce this rule seemingly moving constantly like a pawn on a chessboard. I think some people (not suggesting you) don’t seem to recognise that in congestion, 3 lanes actually provide more capacity than 1, and that it’s not possible or logical to stick to the left lane at all times/conditions. I will yield that the far right lane is sacred and you really do need to be demonstrating some significant overtaking to be sticking in that lane.
> I think some people (not suggesting you) don’t seem to recognise that in congestion, 3 lanes actually provide more capacity than 1, and that it’s not possible or logical to stick to the left lane at all times/conditions.
Rule 268 of the Highway Code touches upon this:
> In congested conditions, where adjacent lanes of traffic are moving at similar speeds, traffic in left-hand lanes may sometimes be moving faster than traffic to the right. In these conditions you may keep up with the traffic in your lane even if this means passing traffic in the lane to your right. Do not weave in and out of lanes to overtake.
Ashley Neal's video on motorway driving provides some good examples of when sticking in lane 2 is OK, provided that you continuously observe and anticipate other road users: https://youtu.be/Vo7sNwf80lI?t=766
What I really like is the lane modification system on the Golden Gate Bridge connecting San Francisco to Marin in California. The bridge is usually 3 lanes each way during normal hours. But during peak hours one is added to the direction of peak traffic flow by moving the lane divider. The bridge then becomes 2-4 with 4 lanes for the peak traffic direction. I think this is doable for other highways as well - at least for the sections where a major artery merges. California drivers are pretty damn terrible when it comes to merging and forcing them to accelerate to highway speed by giving them a lane of their own at these merges with lane switch allowed in only direction will save everyone a lot of time.
As I understand it, (I'm licensed to drive here, but I don't) the way this went down was:
1. Government adds more safety equipment to some test Motorways which allows monitoring lanes and separately varying limits per lane. Unsurprisingly this makes these motorways safer, let's say a factor of X.
2. Government converts hard shoulders into running lanes to save money on some test Motorways. Unsurprisingly this makes motorways more dangerous, let's say by a factor of Y.
3. Government argues that X/Y > 1, therefore adding safety equipment and converting hard shoulders into running lanes, would be on net an improvement. Conveniently the fact that they're doing this because it's cheaper is not mentioned.
We don't accept this sort of arithmetic in other contexts and we shouldn't here. Maybe adding safety equipment is too expensive to justify the reduced danger, but moving to all-lane running is unacceptably dangerous, so, you can't do that, regardless of whether somehow then the safety equipment is magically free.
Previous governments have chosen not to take up obvious safety improvements because they were too expensive. For example, trains in the UK all have the very simplest and oldest SPAD-prevention, the Automatic Warning System, which is activated by an electromagnet (well, technically a magnet which is deactivated by an electromagnet so as to fail safe) but doesn't distinguish between Danger (do not pass this signal) and Caution (expect to find the next signal at Danger) so drivers can get into a bad habit of reflexively cancelling it since they need to pass Caution signals on many routes all the time. Government could have required Automatic Train Protection, a more sophisticated but expensive system which was demonstrated on a small fraction of UK lines and they elected not to spend that money to do the rest. Today most passenger trains have TPWS (which is cheaper than ATP but fairly effective) and a few newer ones are starting to do ETCS (the European system which obviously has production scale benefits, you're buying off the shelf gear that's sold across the continent).
On the other hand, unlike not making them safer, making the roads more dangerous is clearly just a bad idea, and so it became politically harder to defend this practice, hence Rishi now scrapping it.
I'm surprised by the controversy but also don't know any implementation details. The Netherlands allows temporary usage of the hard shoulder as driving lanes during congestion and in my experience this hasn't increased danger nor 'feeling' of it.
That's the other way around: in heavy congestion, using the hard shoulder as a lane is not so bad due to the lower speeds.
All-lane running is the reverse: the hard shoulder is completely missing and you have to just hope that if you break down and can't make it to a refuge bay that a camera operator notices your car stationary in the lane, which is still going at full speed, and closes the lane before someone hits it.
In personal experience of coming up on stopped cars in live lanes, with no signed warning of any kind, they aren't noticed immediately. A stationary vehicle in a lane comes appears very quickly when the lane is moving at 55-70mph.
But (usually) the hard shoulder (emergency lane) is narrower than normal lanes.
Typically (here in Italy) the normal lanes are 3.25 to 3.75 meters wide while the emergency lane is 2.50 to 3.00 (it depends on the period the highway was built, I believe)
So you need to change horizontal lines/signage and make all lanes, including the hard shoulder/emergency lane, the same width, and this means that in "normal" operation travel lanes will be narrower.
> That's the other way around: in heavy congestion, using the hard shoulder as a lane is not so bad due to the lower speeds.
On paper, sure.
In practice it's the worlds best passing lane because the drivers who make the left lane useless as a passing lane don't self select to use a lane that's narrower than the rest, has a ton of merging traffic and a barrier on the harder to see side of the vehicle.
Especially in the UK, motoring is extremely political. The TV show Top Gear was politically formative fir a lot of people here.
Smart motorways are unpopular because they typically include a lot of speed enforcement cameras and lower speed limits, so you can no longer zig zag through traffic at 90 miles an hour.
Thus, smart motorways, pollution enforcement zones, and neighbourhood traffic charging schemes are very controversial. The same people who got exercised about face masks will cross the country to protest them.
These people are the base of the current government, which needs a culture war as the real issues look unwinnable right now so the civil service are under pressure to find a reason to roll this stuff back.
People have been killed in traffic accidents on smart motorways because there has been no hard shoulder available. On the other hand, smart motorways save lives because they reduce congestion - and the calculation is that more people are saved by the lack of congestion than are killed by the lack of a hard shoulder.
The problem is that you can show the faces of the people killed on smart motorways due to lack of a hard shoulder, but the people who weren't in fatal accidents will always be faceless.
Is there any evidence that the extra lane reduces congestion in the long run? The studies I have seen found the opposite: a brief period of benefit before increased volume (jevons paradox) leads to as much congestion as before. Downstream roads can then become even more congested.
I wonder how many lives could be saved by an efficient and affordable rail network?
Dynamic speed limits are a good idea, because they allow a global view of the system to be used to improve it. Otherwise the "optimum" behaviour of individual drivers to get there sooner is to go faster, which, in some conditions, produces congestion which slows everyone down.
However, I don't think everyone believes the limits are there for a good reason. Actual quote I once heard: "they're just playing silly buggers in their control room, ain't they, they don't know anything". Not helped by many other signs crying wolf about obstructions that often aren't there at all.
As for all-lane-running, casual observation of UK driving indicates to me that a blitz on driving standards[1] such as "keep left", "avoid making others brake" and "when you change lane or merge, it's your job to match your speed to the new lane"[2] would be a far quicker way to increase capacity and reduce accidents. And would cost substantially less than the billions spent on smart motorways.
[1]: especially as motorway driving isn't on the driving test and learners weren't allowed on motorways at all until 2018, so most drivers have never had any formal motorway training.
[2]: Not only cars: I see HGVs doing 58 diving into gaps in 70mph traffic (on two lane roads especially) and causing half a mile of brake lights and converting free flowing traffic into nose-to-tail queues every day.
The MIDAS [0] system used to set dynamic speed limits can make for some frustrating driving.
A few weeks back I had a journey on the M42 at evening rush hour where the dynamic speed limit was frequently cycling between NSL -> 60 -> 50 -> 40 -> NSL. Each limit was enforced for 1-2 gantries.
Even to someone who understands the benefit of dynamic speed limits for ensuring good traffic flow, it's not a good experience.
>especially as motorway driving isn't on the driving test and learners weren't allowed on motorways at all until 2018, so most drivers have never had any formal motorway training
The geography of the UK makes it difficult to require that- there are very large areas where it wouldn't be possible for a learner to reach a motorway then get home in a typical 2 hour lesson. Even if you only required learners to go on a national speed limit dual carriageway it wouldn't be possible in some places (far north of Scotland, for instance).
>Dynamic speed limits are a good idea, because they allow a global view of the system to be used to improve it.
That's the theory. However, based on my experiences, it seems the control loop is badly tuned. In general, people's paniced response to a new speed limit needs turning down. All that happens is that people randomly slow down or brake at each new speed limit, and 1/2 mile down the road, there's the regular traffic jam anyway.
I don't think statistics v emotionn is a fair framing.
I'm thinking specifically about the communication around the plan to automatically shut down a lane when a car breaks down in that lane. They cited the time it would take their control center to detect the lane would need to be shutdown as the time it would take to render the lane safe. This ignores that all the cars also have to stop, which takes time.
If you like smart motorways, you'll love my new invention: smart planes. By flying without oxygen masks, life jackets, and seatbelts we can shed a significant amount of weight. This will reduce the emissions per flight and save the planet.
Of course, the passengers will asphyxiate or drown in an emergency, but it happens so rarely!
The "Smart Motorway" has signs to turn this refuge into a full speed lane, leaving a couple of feet for the breakdown area.
I never understood how this could be approved by any Minister who wanted to retain their position, but I guess saving money on new road lanes is more important than the lives of the voters and their families.
Smart Motorways also try to slow traffic on approach to a bottleneck to ease the arrival of congestion before it brings the road to a standstill. In practice, drivers ignore the signs unless they have a speed camera attached to them, making the investment in the technology mostly useless.
Good riddance to this dangerous idea. Don't revisit it while cars have organic drivers.