Stop sign, then acceleration lane.

**Timbuk2**

What I often see turning left on T-roads, where you are on a minor road wanting to join a major road, usually of speed 100km/h, is a stop line, then an acceleration lane that runs for about 200/300m beside the driving lane, before merging in. Here is an example of what I am talking about. Note that it is an acceleration lane, not a driving lane - it ends, with curved arrows beckoning cars into the main lane, but you can't see it in the picture.



My question is, how should these be used? Seeing as there is a stop sign, you are required to look for a gap in traffic anyway. So why is there any need for the acceleration lane? I doubt you are allowed to 'merge' in, like you would with a dual carraigeway, otherwise there would be no stop sign.

Most cars I see, look for a gap, then just go straight onto the road and build up speed - i.e. the blue line!

But should you look for a gap, once you see one, build up speed in the acceleration lane, then move in (red line) - but the fact that you looked for a gap means that if you identified correctly a safe gap, there should be nothing preventing you from moving in at any moment of your acceleration.

What if I'm in the following situation - say I am turning left, waiting for a gap, and there are two cars coming, and behind those there is a big gap. Can I move into this acceleration lane ahead of those two cars, anticipating that by the time I am up to speed, those cars will have passed me out and I can just slot in behind them, into the gap which I have pre-identified?

Hopefully this makes sense - I tried explaining this to my dad and he hadn't a notion what I was talking about

chin_grin

'tis very odd indeed. The only thing I can think of is that the road is like a "dual carriageway" therefore there will be cars in the right lane going at a faster speed and overtaking. Thus you can turn in to the road proceeding in the left lane then eventually merge as the road becomes a single lane?

Probably not it at all!

challengemaster

To me it looks like that section is actually a slow lane which people should be driving normally in..

cruizer101

Thats a funny one alright any chance you can link to the location on google maps, so can see the approach and that.

**Timbuk2**

challengemaster wrote: »

To me it looks like that section is actually a slow lane which people should be driving normally in..

No, it definitely is an acceleration lane. Before the junction, it's like a "deceleration lane" where cars turning left can move into and not slow up cars behind (which is fairly common), then after the junction it's an acceleration lane. Although it doesn't look like it in the picture, the road is a single-laned road, and the 'acceleration' lane ends in about 300m (this is a particularly long one).

Sorry for not linking on google maps! Here is the location.
Here is the link.

(There is a junction on the opposite side of the road that actually uses the same setup!).

Here is another example. A yield sign followed by some sort of auxiliary lane that ends. This 'acceleration' is much shorter, which may make some sense as the road is 60km/h here (approaching major juntion).

There's one of these outside the kilcock road on the way to enfield
I discovered it the hard way :rolleyes:

http://maps.google.com/maps?f=d&source=s_d&saddr=enfield+ireland&daddr=Unknown+road&hl=en&geocode=FWQOLwMdbMSX_ylDJjCOYWJnSDGAfzGXqccACg%3BFcfjLgMdj9mZ_w&mra=dme&mrsp=1&sz=15&sll=53.401908,-6.684623&sspn=0.013151,0.042272&ie=UTF8&ll=53.406232,-6.697326&spn=0,0.042272&z=15&layer=c&cbll=53.406361,-6.697605&panoid=a9soCLp625iFsjWYJdv0LQ&cbp=12,312.44,,0,21.26
(the pic isn't very clear: the far left lane in the pic is the acceleration lane, it ends soon after, scroll to the right and you'll see the 'stop sign' section)

What happens is, you come off the motorway, go around the roundabout, take the enfield exit, and the speed limit is 80 straight away.
About 1 min down the road, there is a T junction where you go straight ahead if you've just come from the roundabout, but traffic coming from the right is stuck at a stop sign, then it wants to turn right onto this main road (or go left in which case that's a different story).

Because the limit is 80 and cars can come tearing down the road, the guys turning right onto it have to get out of the way fast. So they are supposed to go into the acceleration lane to build up to the limit then merge after. If they don't, they can have a near miss with the traffic that's already built up to 80 coming up behind them

I know in your OP you have turning left as an example, it's the same thing I reckon as you said the speed limit is very high.
Yeah you need to wait for clear traffic, but it's easier for everybody if you have room to go from 0 while the already-existing traffic on roads can continue on at 100 unhindered, even if the road seems clear they can "come out of nowhere"

irelandspurs

you need to stop to make sure that no one is using that lane otherwise if you just pulled out someone could be using it.
You should us that lane once you know it is safe to do so.

**Timbuk2**

Thanks for the answers!

Bluewolf, that is a very odd junction setup :eek:
I doubt it's obvious how it should be supposed to be used unless you were familiar with it! At least it wouldn't be to me!

**Timbuk2**

**Timbuk2** wrote: »

Thanks for the answers!

Bluewolf, that is a very odd junction setup :eek:
I doubt it's obvious how it should be supposed to be used unless you were familiar with it! At least it wouldn't be to me!

Yeah I had to see other people using it before I copped on, I once did a right turn onto the main lane and had someone flying up behind me while I was going "what's that other lane for I wonder":rolleyes:

I suppose you would have to know the area, but it makes sense when you think about it

DrivingTestTips: Brian

Always use these lanes to build up speed because there will be less chance of a rear end impact; because, as your moving away from traffic behind, it gives more time/stopping distance for traffic approching on the main road.

Yes I know you shouldn't pull out when there is traffic coming; but we all make mistakes and could misjudge speed of oncoming traffic.