Q line roundabouts
Discussion
Years ago I had a half day with an ex police advanced instructor as a refresher for my ROSPA retest. Around some deserted roundabouts he suggested I try what he called the 'Q' line, which basically meant positioning to the right on the approach then cutting across to the left on the entry, certainly when taking the first exit and I think using it to carry a higher speed into the roundabout irrespective of the exit.
He described it as a police response technique, and it struck me as an interesting idea for driving stuff with flashing blue lights in a massive hurry, even if not relevant for civilian driving.
But since then I've never heard of this technique from anybody else, either as the 'Q line' or under any other name is it/was it really a recognised technique?
He described it as a police response technique, and it struck me as an interesting idea for driving stuff with flashing blue lights in a massive hurry, even if not relevant for civilian driving.
But since then I've never heard of this technique from anybody else, either as the 'Q line' or under any other name is it/was it really a recognised technique?
On an empty roundabout with particularly good visibility to the right, I'll sometimes be looking to straight-line the roundabout, and that's a fairly straight line made up of three points: one somewhere near the right side of the lane approaching the roundabout, one near the left side of that lane as it enters the roundabout and the final point near your apex as you steer to avoid the municipal plantings in the middle of the roundabout.
I've not heard that method given a name ... except a pejorative term coined by my wife.
I've not heard that method given a name ... except a pejorative term coined by my wife.
I'm not familiar with the term q-line or the nuances of it, but I obviously know the terms racing line and straight lining. These are pretty much useless for most roundabouts IMO, as there are just too many variables, so I'd be interested in the description of the q-line to see if it addresses any of my issues with racing/straight lining.
I just treat roundabouts (in terms of line travelled, not in terms of hazards or appropriate speed) as a series of corners joined together. The first is often a kink on entry as the straight road joins the radiused roundabout at an angle, then anything from a kink to an extended bend round the island itself, and very often another kink to the left on exit. Setting yourself up for entry or apex without thinking about the most important one, the exit, could be counterproductive in terms of safety and progress.
If the whole thing is sighted, you can plan the exit line and work backwards from that.
The biggest aim should be to straighten the exit. A racing line naturally runs you wide on the exit, which is fine on track, but that would be towards oncoming traffic. Terrible idea, regardless of how much margin you leave. The principal is wrong. Straightening out the exit as much as possible ensures you don't run wide, and you're winding off lock as the power goes down, not adding more to keep you on your side of the road, or holding off the throttle for longer. This principle of staying wide to extend view, combined with slow in, fast out is no different to any other bend.
Working backwards from that, your entry to the "exit kink" (which is also your exit from the bend round the island) needs to be quite late usually, which means hugging the inside of the roundabout longer than you might think. Your line through the whole roundabout is now starting to look less and less like a traditional straight "racing line".
If you can't see round the island to your exit, then treat it as a blind corner and don't chose your exit line till you can see the exit.
Expect to compromise the line on entry and through the roundabout to get a better exit, better views, better safety bubble etc, but always aim for the best exit you can if your aim is to make progress. A good, straight exit is not only safer in terms of car control, but will translate into car-lengths after the roundabout, where a compromised exit will undo any time saved carrying speed into or through the roundabout itself.
That's how I think of it. I didn't learn that anywhere official, I just worked it out over the years from track driving and road driving combined.
I just treat roundabouts (in terms of line travelled, not in terms of hazards or appropriate speed) as a series of corners joined together. The first is often a kink on entry as the straight road joins the radiused roundabout at an angle, then anything from a kink to an extended bend round the island itself, and very often another kink to the left on exit. Setting yourself up for entry or apex without thinking about the most important one, the exit, could be counterproductive in terms of safety and progress.
If the whole thing is sighted, you can plan the exit line and work backwards from that.
The biggest aim should be to straighten the exit. A racing line naturally runs you wide on the exit, which is fine on track, but that would be towards oncoming traffic. Terrible idea, regardless of how much margin you leave. The principal is wrong. Straightening out the exit as much as possible ensures you don't run wide, and you're winding off lock as the power goes down, not adding more to keep you on your side of the road, or holding off the throttle for longer. This principle of staying wide to extend view, combined with slow in, fast out is no different to any other bend.
Working backwards from that, your entry to the "exit kink" (which is also your exit from the bend round the island) needs to be quite late usually, which means hugging the inside of the roundabout longer than you might think. Your line through the whole roundabout is now starting to look less and less like a traditional straight "racing line".
If you can't see round the island to your exit, then treat it as a blind corner and don't chose your exit line till you can see the exit.
Expect to compromise the line on entry and through the roundabout to get a better exit, better views, better safety bubble etc, but always aim for the best exit you can if your aim is to make progress. A good, straight exit is not only safer in terms of car control, but will translate into car-lengths after the roundabout, where a compromised exit will undo any time saved carrying speed into or through the roundabout itself.
That's how I think of it. I didn't learn that anywhere official, I just worked it out over the years from track driving and road driving combined.
I'd be interested in a diagram of what you're thinking.
For straight and right, yellow and red respectively, I'd take the following as "optimum" lines, conditions allowing.
By description, it sounds like you're thinking of something more along the lines of orange? I could see where there would be benefits in terms of view, as you've more time to get onto the roundabout and look into the exit, compared to taking the tighter line in lane 1, however, I'd expect any gains to be marginal?
For straight and right, yellow and red respectively, I'd take the following as "optimum" lines, conditions allowing.
By description, it sounds like you're thinking of something more along the lines of orange? I could see where there would be benefits in terms of view, as you've more time to get onto the roundabout and look into the exit, compared to taking the tighter line in lane 1, however, I'd expect any gains to be marginal?
Haltamer said:
I'd be interested in a diagram of what you're thinking.
For straight and right, yellow and red respectively, I'd take the following as "optimum" lines, conditions allowing.
By description, it sounds like you're thinking of something more along the lines of orange? I could see where there would be benefits in terms of view, as you've more time to get onto the roundabout and look into the exit, compared to taking the tighter line in lane 1, however, I'd expect any gains to be marginal?
Looks like you have an Australian roundabout diagram, Definitely can't do a Q line here under our rules and you would have to signal for each lane change!For straight and right, yellow and red respectively, I'd take the following as "optimum" lines, conditions allowing.
By description, it sounds like you're thinking of something more along the lines of orange? I could see where there would be benefits in terms of view, as you've more time to get onto the roundabout and look into the exit, compared to taking the tighter line in lane 1, however, I'd expect any gains to be marginal?
Back in the day when Milton Keynes was still developing (traffic was nowhere near the levels it is now) MK was our Racetrack, (sorry Home Town! on our Motorbikes.
My friend on his FZR100 exup - used to be able to get his 'Knee' down (when going straight over a roundabout) on the left hand 'kink' as described, apex of roundabout, then again on the apex of the exit.
It took some doing, as he used to carry sooo much entry speed onto the roundabout, I could only ever manage the roundabout and sometimes the exit bit. It was indeed a quick (flash!) way across the city, although actually quicker to simply straight line them, but impressive all the same..!! Not a chance to do that now, sadly...!
jj
My friend on his FZR100 exup - used to be able to get his 'Knee' down (when going straight over a roundabout) on the left hand 'kink' as described, apex of roundabout, then again on the apex of the exit.
It took some doing, as he used to carry sooo much entry speed onto the roundabout, I could only ever manage the roundabout and sometimes the exit bit. It was indeed a quick (flash!) way across the city, although actually quicker to simply straight line them, but impressive all the same..!! Not a chance to do that now, sadly...!
jj
Turning left on the yellow line from the offside lane would not be obeying the road markings....likewise turning right on the red line would be ignoring the road markings......
Maybe think about the cambers of the road on the approach to the roundabout, the camber of the roundabout, and then camber exiting roundabout to work out what speed could be taken on, in what gear to accommodate the weight transference in order to keep control....this will change owing to surface of road, weather, stuff dumped on road such as oil/diesel, wear on your tyres, weight of the car (1 person or 4 up, fuel load/boot load) and of course other traffic
Maybe think about the cambers of the road on the approach to the roundabout, the camber of the roundabout, and then camber exiting roundabout to work out what speed could be taken on, in what gear to accommodate the weight transference in order to keep control....this will change owing to surface of road, weather, stuff dumped on road such as oil/diesel, wear on your tyres, weight of the car (1 person or 4 up, fuel load/boot load) and of course other traffic
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