Motorway sliproad, stay same speed, move over or slow down?

[WyclefJohn]

This is more of a question about what do most people do, rather than what is reasonable.

Yesterday, I was driving up a sliproad to join a motorway, and I saw what looked like I big gap in front of a van, but I was going a bit slower (maybe 5mph or so, although I was getting faster), so the van was gaining on me a bit. I was fully expecting him to slow down a touch and let me in, and I was getting a bit nervous as I thought I would have to brake sharply. Eventually they did and no problem, but I could have caused an accident, but my strategy hinged on the strategy of the other driver (or player, it's a bit like game theory).

My DP and I then had a conversation about what is the reasonable thing to do as the driver on the motorway in the similar situation. If you're on the main road, and you see a car coming on, you're going to clash, there are three strategies

1. Move over if there's space
2. Slow down
3. Keep going at normal speed, and force the person coming on to react

My DP argued the right thing to do is 3) keep going. However, I think that "most people", would either follow strategy 1) or 2), to allow someone on.

I think my DP is technically correct, but moving over a slowing down seems more natural. I also get it can vary from situation to situation (difference in speeds, how much braking is required). What do most people do and what is right in this situation?

I was taught that once in the motorway, you should consider slip roads to be hazards, and if you can see traffic joining, you should move over if possible. If not possible, stay in the left hand lane, and maintain your speed to allow the joiners to adjust their speed as necessary to join safely.

It’s actually quite easy on British motorways. I’ve lived in the US, and they have hideous junctions where the leaving and joining traffic use the same slip road for a 300 yard dice with death at 50mph. Plus no-one indicates or moves over - they are signs of weakness! (As explained by colleagues)

@CuboidalSlipshoddy wrong - it is illegal to stop on the slip road. Rule 270 of the Highway Code.

Thanks Fairfax. Hard to square that with 259 "give priority to traffic already on the motorway", though.

As I said earlier if you genuinely can't get out (and I've never called me across that scenario despite many thousands of miles on the motorway each year) continuing on the hard shoulder is the safer option

There is a very short sliproad joining a dual carriageway here and people (usually men in works vans or Audi’s) come flying up it with no intention of looking to see if anyone is in the lane. They just force you over and I’ve had a few times that I’ve had to do a panic shunt into the outside lane even when there hasn’t really been space to move over due to these inconsiderate arses. It’s so busy it’s not always possible to stay at a consistent speed when you think someone is about to ram you over.

and I've never called me across that scenario despite many thousands of miles on the motorway each yea

Indeed. I commuted on one of the busiest pieces of motorway in the UK for fifteen years and never encountered it, hence my embarrassing highway code lapse. It's a theoretical situation, like "what happens if an alien spaceship lands on the carriageway while Michael Jackson is moonwalking down the hard shoulder, eh?"

I have, however, on three occasions encountered cars reversing up slip roads. On each occasion, I am afraid to say, elderly drivers, on roundabouts where main roads cross a motorway. Why the fuck they can't continue on for three miles to the next junction, having made the mistake, I don't know.

I had to stop on a dual carriageway slip road the other day because there were 2 lanes of traffic travelling at 60mph and noone in the nearest lane would slow for me. There was no hard shoulder. It was scary but what else could I do? I had to sit there for what felt like forever and wait for a big enough space to pull out and get up enough speed.

I always move over if possible but if not and I saw someone joining, I'd slow a little if safe to do so.

The driver on the road should either speed up to overtake you and give space behind or slow down and give space in front (assuming they can't move over)

I was taught to either speed up on a slip road, or slow down and tuck behind if you are both going the same speed.

I had to stop on a dual carriageway slip road the other day

Which is, presumably, legal, or at least differently illegal: the rule referred to above relates specifically to motorways, presumably because the slip road counts as motorway as you have passed the blue "motorway restrictions" sign at the start of the sliproad. That's not true for an A road, say: the slip road is just like a tee-junction, but set at an angle.

I must be really mean, i don't slow down, move over etc. If thy have to stop then so be it.

I wouldn’t brake to let someone on because that would be dangerous.

However when I’m on a motorway and coming up to a sliproad I anticipate people will be joining and try to ensure I’ve got a decent gap between me and the car in front to allow someone in, so I may ease off a bit but in plenty of time.

I hate it when people barge their way on assuming I’m going to move over but the middle lane is rammed and I can’t but they just keep coming.

You don't need to brake just anticipate the slip road and let up off the gas a bit or move over. The number of idiots who trundle past at 50 or 60mph and ignore the oncoming traffic is downright dangerous. I had it today. Someone decided they were going to match my speed off the sliproad in heavy traffic. I near on shat myself coming onto the A road!

must be really mean, i don't slow down, move over etc. If thy have to stop then so be it.

I think that is a bit mean to be honest. I appreciate the argument that people should plan in advance so they don’t have to stop. Certainly in 20 years of regular motorway driving I’ve never messed up to such an extent. But people make mistakes, maybe they’re a newish driver, etc and not helping someone out to such an extent puts them in a dangerous position. If they have to stop they’re at high risk of being rear ended at speed either on the sliproad or when they join the motorway at a slow speed as they can’t get up to speed quick enough from being stopped.

It's a theoretical situation, like "what happens if an alien spaceship lands on the carriageway while Michael Jackson is moonwalking down the hard shoulder, eh?"

I might be misunderstanding the theoretical situation, but imagine there is traffic in the inside lane going at 70mph, the road is busy so cars are just about following the two second rule, in that situation it would be difficult to get out safely, (as you'd be less than the two second rule), without some adjustment from both the driver on the slip road, and the drivers on the motorway.

I've never had to stop on the hard shoulder, but I've certainly had occasions where I've had to pull out requiring adjustment from cars on the motorway.

the road is busy so cars are just about following the two second rule, in that situation it would be difficult to get out safely, (as you'd be less than the two second rule),

Are you saying that you regard it as unsafe to join a motorway unless there is a four second gap you can slot into (ie, such that you have two seconds in front of you and leave the person behind you two seconds as well)? At 70mph, that would involve cars leaving 136 yards between them (30 car lengths, roughly) in the throats of junctions.

The only realistic thing to do there is to go into the gap and then assume that over the next mile or so it'll sort itself out. A flow of traffic running at 2 seconds' headway is not going to magically thin out to 4 seconds' headway every couple of miles on a busy motorway.

Are you saying that you regard it as unsafe to join a motorway unless there is a four second gap you can slot into (ie, such that you have two seconds in front of you and leave the person behind you two seconds as well)?

In effect, I am saying that I suppose. I would potentially find it a bit unsafe to follow a car with say a 1 second rule. Stopping distance at 70mph is 96m, which works out to be 3 seconds if I'm not mistaken (the Highway Code states "The safe rule is never to get closer than the overall stopping distance; allow at least a two-second gap between you and the vehicle in front on roads carrying faster-moving traffic and in tunnels where visibility is reduced)

The thing is, you should be aware of what's happening around you. The person joining should speed up to motorway speed but with one eye on the gap they are aiming for, may have to hang back a bit to merge in.

The drivers in Lane 1 almost certainly will not be at 96m or even 73m stopping distance apart, so I think if you see someone struggling to merge into the small gap you have left them and running out of slip road, you should make space if you can safely do it.

I always try and move over if I can, but wouldn't slow down if I couldn't. The slip road is actually called the 'acceleration lane' as it is there for the driver joining the motorway to use to get up to speed and move into the inside lane in a suitable gap.

There are very few motorways or dual carriageways where the gap between cars is 200m or more during the daytime. Usually, I would join, match my speed to the flow of traffic in the lane, and then establish a gap (or overtake if there are slower moving vehicles in the left hand lane). There's also rarely a 4 second gap if you have to change lanes- especially in the Easter holidays!

Although maintaining a stopping distance is important, it is very rare for traffic on the motorway to come to a dead stop with no warning and waiting for huge gaps to do anything is pretty unrealistic. You can generally spot queuing traffic or an accident well in advance, and overhead signs will also warn you of potential hazards. On other roads, there aren't the sort of hazards most likely to cause an emergency stop. This means it's usually safe to join a lane with less than a 2 second gap and take a few seconds to establish this gap once you are in the lane.

It does sound like you don't have much experience of slip roads etc- I was lucky that when I was learning there was a long stretch of A road with two lanes that was joined and exited by slip roads, so I could have lessons on this type of road. This really helped me prepare for motorway driving. If you're not familiar with this type of driving or it makes you feel nervous, perhaps some lessons would help.

Thanks, but honestly, I think my driving on motorways is pretty good, both as someone coming onto a motorway, and as a driver on the motorway anticipating cars coming onto the driver. I think in this one instance, I underestimated a bit how fast the car was going. But as I said, he slowed down a bit, which seems to be what you are suggesting above he should have done ("it's usually safe to join a lane with less than a 2 second gap and take a few seconds to establish this gap once you are in the lane.")

I was more talking about what you should do- i.e. creating your gap if there's a car ahead of you- but yes, I agree he should have done the same thing or overtaken you if he wished to continue at a faster speed.

I guess I am used to joining busy a-roads and motorways where there are rarely very large gaps and this just seems like a non-event to me? Which is why I thought you might be lacking in confidence?

I do agree it's nice to help people out by moving over, and this is always what I do if I have the space to do so. I'll even move 2nd-3rd lane to help others move over as well if it's busy and there's lots of slower moving traffic. However, if I couldn't move over and there was a reasonable gap I'd keep going at a constant speed as this is the most predictable thing for the joining driver and other drivers around me- the joining driver can then chose how to adjust their own speed. If there was a gap behind me and I ease off but they also ease off then that doesn't actually help anyone!