Conference terri::cars_uk

    I think if everyone observed some common sense (ie. in a perfect
    world) we wouldn't need lights on roundabouts. Roundabouts should be
    self-governing, if you see what I mean.
    
    I think the lights are to make up for the times when someone finds
    themselves across the road and blocking exits/entrance onto the
    roundabout.
    
    Maybe some form of 'hash-boxes' at the junctions would work better? Hmm
    I dunno.... I'm sure the people who are putting these things up
    everywhere have some idea at to what they hope to achieve. But I would
    agree with you, lights on roundabouts are a pain in the backside when
    they're not doing their job (ie. traffic is blocked).
    
    Cheers,
    Dan

I don't know what the principle behind it is, but the setup at Winnersh seems 
to work well.  Some of the lights are operated by in-road sensors, so people 
aren't kept waiting for ages just for no cars to go through on the green light.

The only thing that annoys the hell out of me, with regard to this particular 
roundabout/junction/whatever, is the moronic practise (abundant in Reading) of 
having 2 lanes approaching the lights, and only 1 lane on the other side.  This 
just encourages races from the lights, and invariably results in someone 
beeping their horn at someone who is pushing into *their* lane... Now, they've 
stuck Gatsos up to stop people racing away, or jumping the red.  This means 
that you can't even accelerate your way out of a crash, meaning that you have 
to brake, and risk Nigel Mansell behind you, crashing into your rear end.


PAH!

    The only answer is to fit steel girders around the outside of
    everyone's cars, and let 'em fight for the position.
    
    It's the only answer.
    
    Dan$sensible_suggestions_man

No need in my motor.  It flicks those pesky Micras out of the way with an 
assertive slap.

    As far as I know the Gatsos at traffic lights dont do speed checking.
    They only check for people passing a Red light. Not many cars could
    accelerate to beyond 30mph while still in view of the camera.
    
    Road Junctions only work when the exit roads are not congested. As soon as
    any exit road blocks up anything waiting to go down the road is going to
    block other traffic that wants to go along some other non-congested
    route. The only way to prevent this happening is to separate the
    traffic before it can block other traffic. E.g. separate lanes on the
    approach to the junction. Other forms of control (E.g. lights and
    strictly enforcing correct lane usage) can improve things somewhat, and
    can greatly influence flow through a junction when the exit roads are
    not blocked.
    
    I agree completely with the number of lanes thing. It is absurd to
    force traffic to merge lanes in a junction. There should be a
    requirement that there be only one entrance lane at any entrace leading
    to any exit lane. You should select your lane before reaching the
    junction, and have no conflicts while going through the junction. This
    would reduce the amount of concentration needed to pass through the
    junction safely - the driver would be able to concentrate on getting
    through quickly without having to worry whether the car in the next
    lane was going to cut in front of him. Arrows and road signs should be
    strictly enforced (using GATSO cameras where appropriate). Changing
    lanes should only be allowed between junctions.
    
    Andrew

    Roundabouts work fine when there is a fairly even flow of traffic coming
    on at each point.  Every day I have to queue when joining a roundabout
    because of continuous traffic from my right.  If something could restrict 
    their flow, I would not have to queue.  I would rather the lights be 
    before the approach to the roundabout, rather than actually on the 
    roundabout itself (ie once on, business as usual...)
    
    Jc
    

    re .6
    
    Sounds like your roundabout is a case where there is a lot of traffic,
    but no exit road is clogged up. This could be improved by a set of
    lights (unlike J11).
    
    Andrew

    I would agree that the lights at winnersh help traffic flow if it is
    *really* severe but have you noticed that when the lights break and
    they cone off the road that goes through the roundabout then you get 
    a much smoother flow. Normally, if you are turning right at this 
    roundabout you can count on getting caught at one, if not two, sets
    of lights (unless you put your foot down).
    
    Also, I've seen a few nasty looking accidents on this roundabout but
    these are probably due to people misunderstanding the lights and
    jumping a red light (there are a lot of lights!). I've seen many a car
    jump the lights without realising it.
    
    Personally, I'm in favour of turning it back to a normal roundabout.
    
    Cheers,
    Barry.
                                         

    On the subject of roundabouts, the one under the IDR as you head south
    towards the Basingstoke always strikes me as a strange one. The bulk
    of the flow is simply leaving the IDR, and traversing the roundabout to 
    leave on the third exit for the Basingstoke Road. Usually this is two
    full lanes of traffic in the morning, and very little goes right round
    the roundabout. 
    
    Recently, however, I have witnessed two drivers (both of heavy trucks)
    that probably didn't know the area, and tried to go right round the
    roundabout from the nearside lane! The result was that they rode right
    over a car in the other lane which followed the 'normal' behaviour
    here, and turned left.
    
    cheers
    DaveT
    

    Hi,
    
    	A couple of roundabouts near here have started and then stopped
    using traffic lights. J16 on M4 (turning to Bristol office) had them
    going for a few weeks and on average they added 5 minutes to my journey
    time due to the queue caused going back on to the motorway in peak
    times, I don't know whether they improved anyone elses but once of the
    motorway the congestion was worse through to the A38. Now the lights
    have gone off the whole thing seems to be self-governing better.
    
    	In Taunton (J25) the lights have been due to go on for 4 months,
    and the sign saying starting operation Octover 27th, 1994 has now been
    replaced with 'next Monday' ! We will see ......
    
    	Euan

    These light-controlled roundabouts only work when 
    there is an imbalance of entry
    there is heavy traffic
    someone has studied & tuned the flow
    the programs are varied to match tidal patterns
    
    If you dont have all 4 criteria, then it ends in tears. I am convinced
    that there is a lack of understanding by the decision-makers, which may
    cause poor design & under-investment, followed by poor decisions.
    I agree that Yellow Boxes should help, & these seem to have gone out of
    fashion. If the busy junctions were designed *properly*, then they
    would have left-turn-only sliproads which bypass the roundabout. These
    would cut down the roundabout traffic by about 25%, which would move
    the saturation-point further up the cars-per-hour scale exponentially.
    
    My pet junctions are M4 j11 & 12, these have been dramatically improved
    by Roundabouts+lights, but had their teething problems. Poor lane
    alignment is the most glaring one.
    
    Tony.

    
    re .-1 
    
    Is this the same J11 that I drive through????? Since the lights have
    appeared I have ended up sitting on the M4 behind a queue of cars that 
    are going 'straight ahead' on average twice a week. On the way home in
    the evenings, it is like russian roulette whether you get hit by
    someone coming around from Basingstoke direction and running the
    lights. Then of course you have the narrow lanes, which would not be
    too bad in themselves if they bothered to paint the lines around the
    curves where they are actually needed. 
    
    I suppose I could be a little touchy on the subject of lights because I
    live in Thatcham, where the A4 has been endowed with 5 revised sets of
    traffic lights over the past few months, with another set coming online
    very shortly. 
    
    Can anyone explain this insanity to me? In one place they have just put
    a pedestrian set of lights almost directly on top of a pedestrian
    underpass.
    
    Terry
    

>Then of course you have the narrow lanes, which would not be
>too bad in themselves if they bothered to paint the lines around the
>curves where they are actually needed.

Narrow? They seem prefectly adequate to me. There's plenty of room for three
cars, admittedly it gets tight when you have two lorries going round together
but that does not happen very often. Perhaps you have mistaken the average
motorists inability to go round corners as a problem with the layout?

Dave. 

    
>> Perhaps you have mistaken the average
>>motorists inability to go round corners as a problem with the layout?
    
    I think you have identified part of the issue there. I for one would
    rather that the road system were laid out with some eye to the
    capabilities of the average driver..... 
    
    

re.14:

>I for one would rather that the road system were laid out with some eye to the
>capabilities of the average driver..... 

It's impossible. The wider the lanes around the roundabout, the more lanes
traversed by the "average" driver. You'd think the roundabout by DEC Park would
be wide enough for two vehicles, but last night a young lady still managed to
cut me up. Of course, people like that never have accidents and consider
themselves safe because they never see the avoiding driver getting hit by the
following car, and even if they did they would not associate it with their
actions.

I have a pet theory, that there is a large proportion of the population who are
just not capable of the awareness necessary to drive a car, thus the blinkered
approach.

Dave.

    
>>I have a pet theory, that there is a large proportion of the population who are
>>just not capable of the awareness necessary to drive a car, thus the blinkered
>>approach.
    
    Don't start me on this............
    
    I've always found it incredulous that the DoT don't enforce a driving
    test every 15 years for example, increasing this to every year when 
    reaching the age of 70.  There are so many older drivers out there 
    who cause frustration and danger on the roads simply because they aren't 
    aware of other road users and the effects of their inability to 
    use the roads with the other drivers.
    
    julia
    

    The dreaded DECpark Reading roundabout is behaving very strangely since
    traffic lights were installed.  Before 9 a.m. there is little
    difference to we northbound travellers.  After 9 a.m. when the lights
    should be switched off in my opinion, matters are worse.  Even though
    the exit the other side, towards DECpark, was clear, it took me 30
    minutes to cross the wretched roundabout the other day.  This was
    arriving in the queue at 9.30 a.m.  Arrgh!  And on Sundays when I have
    to wait at red lights while the roundabout is empty, my radiator boils
    over.
    
    My belief, picked up from a session with the country council when
    we were once trying to sell them something, is that that traffic lights
    appear because their unit cost is very convenient for spending every
    last penny of the budget at the end of the year.
    
    Ken (normally calm, but not about traffic lit roundabouts!)

Last night, I noted the number of cars who had to stop at the J11 roundabout.
I was stopped on entry from Basinstoke Road and on the exit to M4 west 
bound. In addition, traffic from all other entry points were stopped even
when there was no traffic on the roundabout. (This was a dynamic situation
where different cars were stopped at different times). That is, some 8 cars
in the minute or so I was in the environment of the roundabout were
unnecessarily delayed. It was 18.45 - i.e. not in the rush hour.

The traffic lights at the bottom of my road in Thatcham annoy me. They
have recently replaced a mini roundabout. I do not notice an increase
in traffic throughput. On problem with traffic lights is the inability
to match your entry with a gap. Rather, you stop, wait for the lights to 
change and then there is a race to the next set.

The lights which most annoy me are on J12 M4. Coming from Theale on the
A4, I have to turn right at the roundabout. The lights between A4
towards Reading and the M4 East bound entrance are so close together
and phased such that it is difficult to get from the right lane to one of
the left three lanes to head off towards the M4.

	Dave

 

The setup on the M11 J8 roundabout is another classic example of how
not to do it.  The exits are frequently blocked by traffic queueing
up at the traffic lights on the roundabout, and what's worse is when
an exit is only *partially* blocked, causing cars to swerve into
the inside lane to avoid the unseen parked vehicles around the corner.

What's even more annoying is having to wait several minutes at a red
light to enter the roundabout at 1am, giving way to nothing at all.
I've finally resigned myself to what all the other locals do at off-
peak hours and just ignore the lights; I just hope there's no cameras
around!

Chris.

    
    Surely it'd be easier just to implement the flashing amber lights like
    the rest of the world?
    
    C.

    RE: "implement the flashing amber lights like the rest of the world?"
    
    In the US (Mass accutally) those flashing ambers == steady green  :*)