Changes to road desigs & markings - making things worse

[Funk]

I've noticed over the last few years that there seems to have been a change in the way road markings are designed/implemented, particularly on roundabouts.

Several locations near me have lane markings on them that actually appear to create problems rather than solve them, such as lanes 'spawning' mid-roundabout and the decision to make a three-lane approach merge the two right-hand lanes after the exit. The former causes issues with drivers finding themselves having to make a 'lane change' or finding themselves in a lane that isn't going where they thought it was. The latter causes congestion and issues as vehicles exiting a roundabout find themselves having to suddenly merge with the lane next to them.

Here's an example of the first issue:



I've driven this roundabout thousands of times over the last 30 years - they recently completed works to put in a pedestrian crossing (much-needed) but they've also fked with the lanes on the roundabout itself. Since the changes a few weeks ago I've had several near-misses as drivers find themselves in the 'wrong' lane and immediately try to cross into the one they actually needed to be in (and which already contains another car).

For example, both lanes approaching from the west have the right to go straight across - however the left hand lane now tries to send traffic to take the north-bound exit so cars have to cross the lane divider at the last moment to continue east. Except more often than not there's already car in that lane that's now avoiding the 'new' lane that appeared in the middle of the roundabout. It's probably also confusing for the traffic coming from the north heading south as it looks like a car in that east-bound lane from the west is going to take the exit to the north.

Basically it's a mess and anecdotally I've gone from never having anyone try to drive into the side of me there for decades to having several near-misses in just a couple of weeks. The only way to drive the roundabout appears to be to pretend the lane markings don't exist and just drive through as if they weren't there - which means they're irrelevant/useless/wrong.

An example of the latter is here near the Shoreham flyover near Ricardo:



Approaching from the east, the nearside lane expands into two lanes at the roundabout (arrow on the right) but on the exit, it's the centre and outside lanes that merge (arrow on the left). It's the same for both directions.

Before this was built (for a development that was ultimately cancelled, ironically - there was supposed to be a large IKEA and loads more houses on the development to the south) they had the opportunity to improve traffic flow through here as it's a congestion nightmare during rush-hour. What they've done is made it worse, not just with the way the lanes are laid out but also nonsensical traffic light phasing which interrupts the main flow of all the traffic using the A27 and causes tailbacks and queuing. It's a mess, frankly.

I know we have some folks on here who are involved with road design/traffic management - anyone able shed light on why some policy-maker somewhere thinks this is a good idea? It feels like new roads are being designed by people who've never actually driven and don't understand how things actually work in the real-world environment.

It's causing chaos and confusion and unfortunately the poor road design decisions made today will cause issues for decades to come.

[stogbandard]

I reckon it’s because it’s designed using software that theoretically makes this an efficient design. It doesn’t work though because the software doesn’t anticipate how drivers will use the roundabouts in reality. Many roundabouts these days are designed to be entry path overlap nightmares because following the lane you’re meant to be asks for taking a path that steering feels less natural. Presumably this is to slow traffic speeds but drivers react by drifting across lanes instead.

[chris1roll]

I give you Huntworth roundabout near Bridgwater.

https://maps.app.goo.gl/gTLK6ypSdrmzmPFQ7?g_st=ac

If you are coming from the M5, if you want to head into Bridgwater (A38N) then if you follow the road markings on entry you have a large chance of then being in the wrong lane as soon as you are on it.
The fourth (right hand) lane marked A38N/Services instantly becomes Services only, which results in near misses as people try to move left once they realise.
The third lane guides you to the 2nd lane on the exit, if you choose this then you are technically correct but look out!
The second lane, marked A38S and Wilstock, then becomes Wilstock and A38N.
So if you start in the third lane you have to watch out for people cutting over from the right because they don't want the services, as well as people undertaking on your left (as you are leaving time to react to people cutting left) as you get towards the merge point.

I can see how they _wanted_ it to work, with everyone going North moving left as soon as they enter (aside from those wanting the services,
Like this:

But that was hard enough to draw! Let alone get people to do it with no prior knowledge and/or time spent studying it.

In practice it simply cannot work as on entry there will always be people to your left (wanting wilstock) at all but the quietest times.
It would be much safer if it was
1 A38S;
2 A38S/Wilstock/A38N;
3 A38N;
4 Services.

When it is busy, the safest thing is to take the second lane (which is marked to go in the literal polar opposite direction) which magically turns into the lane you need with no lane change required. Then you don't need to have eyes like a rabbits.

You should not need local knowledge to be able to negotiate a roundabout correctly first time. If you do, then it is a failure of design, road markings, or both.

[Rusty Old-Banger]

Very often, local knowledge, or simply knowledge of how the locals use the system, will dictate how a system is modified.

Will come back to this in a week to explain further, on holiday at the moment so just wanted to add a small placeholder.

Back to the sun.

[Funk]

I'll be interested to read your comments. All I can say at the moment is that it's been fine for decades, changes have been made and there are now issues...

[FiF]

There was a long discussion about this on the slow drivers thread.

Part of the issue is that there are two systems, circulatory and spiral. Without local knowledge there is no indication on the approach to an island which system is in operation and there are subtle differences how they should be treated.

Many drivers get confused by the spiral system as they don't understand the lane markings which will have the various exit destinations marked in the lanes and if there are upright signs they should correspond to the lane markings.

The basic principle is that as soon as you are in a lane which is marked for your destination, then stay in that lane whilst going round and the lane will spiral outwards and lead you to the exit and off to desired destination.

Where people go wrong is trying to drive like a conventional circulatory island and keeping close to the island until they get near their exit then moving to left for exit. Particularly if they are going a long way round the island, get confused by new lanes starting on the right. Start swapping lanes and sometimes collisions result.

There's a number of YouTube videos on circulatory roundabouts, not so much official guidance though.

https://youtu.be/EOeBLQpUtJ0?is=BkWAUESAc36Zr_of

[Pica-Pica]

Thanks FiF for that video link. I don't come across spiral roundabouts much, but they have made sense when I have encountered them. I would comment about that Ashley Neal video; I WOULD indicate when taking my exit and leaving the roundabout. That removes any doubt for those who may be unused to the roundabout.

[FiF]

I don't agree with everything he says, for example the bit where the left lane on entry services the first two exits. Not always the case.