Roundabouts or traffic lights?

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horizon
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Roundabouts or traffic lights?

Post by horizon »

I always thought that it was simply to do with traffic volumes but apparently not:

http://www.theguardian.com/cities/2015/ ... ts-way-out
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661-Pete
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Re: Roundabouts or traffic lights?

Post by 661-Pete »

Well, apart from wrong-footing himself in the first few lines of the article ("since resuming the school run...") the writer of this article presents a reasonably balanced view of the situation. That guy he cites in the article, Kevin Beresford, is by all accounts a total pr@t. His so-called "Roundabout Appreciation Society" reminds me of the equally aptly-named "Pylon Appreciation Society". Long may they prosper - in each other's company! :lol:

Personally, I can cope with small roundabouts, where there's little risk of being overtaken by a following motorist whilst actually on the roundabout. It's the larger ones I despise. But you have to live with them. Yes - bring on the T/Ls - or at the very least increase the number of RAB's with T/Ls placed around their circumference. Those are at least a shade better for cyclists...
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DaveP
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Re: Roundabouts or traffic lights?

Post by DaveP »

661-Pete wrote:or at the very least increase the number of RAB's with T/Ls placed around their circumference. Those are at least a shade better for cyclists...


Gosh! You've surprised me with that one...
There are a couple near me. Fair enough, they are pretty big specimens, but I find them stress inducing even in the car. The lights just make it really difficult to accomplish the appropriate lane changes, especially when preparing to leave the Rbt. I keep finding myself stationary with queues building along my near side in the lane I'm trying to get into. Judging by the violent accelerations shown by more than a few other drivers I'm not alone in this.
Wouldn't dream of trying to cycle them - far too much irregular stuff going on!
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661-Pete
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Re: Roundabouts or traffic lights?

Post by 661-Pete »

DaveP wrote:Gosh! You've surprised me with that one...
There are a couple near me. Fair enough, they are pretty big specimens, but I find them stress inducing even in the car.
Hmmm... perhaps you've caught me out there - I'm trying without success to recall whether I've recently negotiated a RAB of that type, by bike. My line of reasoning was, it reduces the risk of motorists cutting across you when joining the RAB, because they'll be stopped from doing so by the T/Ls. OK it seems there are other factors...

Regarding the matter of RABs in the USA: from my brief visit last year (by car: no cycling :( ), I recall that the only RABs we passed were on relatively minor roads, single carriageway roads with not much traffic. The busier S/Cs mostly had US-style intersections with T/Ls (and the 'turn right on red' rule which in itself could be a hazard to cyclists!). On the Freeways (dual carriageways), the junctions were invariably motorway-style with flyovers. But possibly things are changing over there. I think much of the USA is very cycling-unfriendly for those who want to cycle on roads.
Suppose that this room is a lift. The support breaks and down we go with ever-increasing velocity.
Let us pass the time by performing physical experiments...
--- Arthur Eddington (creator of the Eddington Number).
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mjr
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Re: Roundabouts or traffic lights?

Post by mjr »

661-Pete wrote:My line of reasoning was, it reduces the risk of motorists cutting across you when joining the RAB, because they'll be stopped from doing so by the T/Ls.

:lol: Pull the other one, it's got bells on! They see it's only a cycle about to enter and jump the red light! Roll on red light cameras issuing semi-automatic fines and points.

Also, around larger roundabouts, the lights often seem timed to give a green wave for the optimal capacity motor vehicle speed, which is usually faster than I can cycle, so I get held at every light... except when they go into detector-activated mode at quiet times, which usually fails to detect cycles.

Of the two pure forms, I think I slightly prefer traffic lights for large junctions and roundabouts for small ones, but really I'd prefer cycle bypasses of both, as far as possible. :)

I think much of the USA is very cycling-unfriendly for those who want to cycle on roads.

I've not ridden there much (only NY and Miami, I think) but it seems very mixed and inconsistent, even worse than the UK. In urban areas, there are plenty of non-carriageway routes and carriageway lanes are often much wider than ours, which reduces conflict... but disrespect towards cycling and cycling infrastructure often seems far greater than here, increasing conflict. Motorists often seem to expect you just to vanish out of their way if you're not in a car. Not content with the "jaywalking" farce, the situation in some cities is so bad they've put up loads of large signs warning of the fine for blasting past a pedestrian on a crosswalk! https://goo.gl/maps/Jwitgj9qCUR2
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PRL
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Re: Roundabouts or traffic lights?

Post by PRL »

DaveP wrote:
661-Pete wrote:or at the very least increase the number of RAB's with T/Ls placed around their circumference. Those are at least a shade better for cyclists...


Gosh! You've surprised me with that one...
There are a couple near me. Fair enough, they are pretty big specimens, but I find them stress inducing even in the car. The lights just make it really difficult to accomplish the appropriate lane changes, especially when preparing to leave the Rbt. I keep finding myself stationary with queues building along my near side in the lane I'm trying to get into. Judging by the violent accelerations shown by more than a few other drivers I'm not alone in this.
Wouldn't dream of trying to cycle them - far too much irregular stuff going on!


The Hammersmith Gyratory used to be really scary for cyclists and lights have made it not at all bad (led the London Freecycle feeder ride that way his year) . You do have to get into the correct lane though. Sufficient congestion keeps speeds fairly low.
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Re: Roundabouts or traffic lights?

Post by Bmblbzzz »

A gyratory is rather different from a roundabout, though. If we're comparing t/s with rabs at single junctions, rather than whole systems, then I think... it depends on size and shape. Two of the key factors IMO are width of the circulating carriageway and the angle of deflection at entry (the narrower and the straighter, respectively, the better for cyclists and for pedestrians trying to cross the roads).
DaveGos
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Re: Roundabouts or traffic lights?

Post by DaveGos »

Yes I read the article . I had been searching for the reason for all the traffic lights springing up for some time. Its a bit of a pet subject of mine. My nearst town is Telford . When I moved there it was all roundabouts and barely a traffic light n the whole area. Now we get more traffic lights every day. A little background I drive about 18000 miles a year and cycle about 8000 miles a year and race in alot of time trials.

In Telford they have done many junction changes to TLs and keep getting government grants to do more ( 6 announced today) . These result in roadworks for about 6 months, confusing junctions and no improvements in traffic flow , often the traffic flow is worse and 2 of the 6 "improvements" of late are rehashes of previous attempts, its not that we even have that serious traffic here in the rush hour you may have to wait 2 mins at the most at the worst junction . In one case to do a right turn used to be right turn at the island , now you negotiate 3 islands and 9 sets of traffic lights ( i kid you not) . This was all to accommodate a rail freight terminal that 10 years later has never been used. They keep announcing these "improvement" schemes instead of tackling the many serious road improvements that everybody is crying out for like the dualling of the a5 around Oswestry ( built as 3 lanes but they have white painted out one lane)

I think its all about control , they like the controlling option . I dont buy the cyclist line as they never spend any money on any proper usable cycle infrastructure. While I understand the need for TLs on multilane roundabouts , they are putting in endless TLs on small junctions , these are all one direction at a time ( IE 4 changes for a complete cycle) and many try to be so called intelligent IE no car no change , so dont work for motor bikes and cycles. The so called improvements are wastig millions of pound when we are closing libraries etc and cause months of disruption.

For Shropshire and Cheshire Time trialing they are soon to "improve " Shawbirch roundabout , which is key to most of our time trial from 10s, 25s, 30s, 50s 100s , 12 hr and 24 hrs

TLs also waste lots of power and require more maintenance and accidents are worse when they happen as they are side on and not at a similar angle and tend to be faster as people put their foot down to jump the lights.
Bmblbzzz
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Re: Roundabouts or traffic lights?

Post by Bmblbzzz »

I think there is a safety aspect, it's not just control. There's a roundabout on the inner circuit road here (Bristol), where a slip road comes off a city centre dual carriageway to a medium-sized roundabout with a single-carriageway road. At some point in the 90s TLs were put in on the roundabout, but this summer they were out of action for a week due to some fault. I didn't have any occasion to use it during that week, but it was generally reported traffic flowed more smoothly; however, people found it much more difficult to cross the road, especially the elderly/disabled/be-luggaged/otherwise slow of leg, and cyclists were saying it felt more risky – though I don't think there were any actual incidents during that time. I just mention this as an example that TL control of roundabouts can work to cyclists' and pedestrians' benefit (though there obviously remains the question of how a TL-RAB compares to a plain TL x-roads).
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