Oxford quickways

[Stevek76]

A study in London estimated that advisory paint was indeed more dangerous than nothing at all. Mandatory paint was found to no overall affect.

And posts? Kerbs?

Some benefit for light segregation, more for full

Study (and note limitations which are reasonable - parts of the route/destination estimated via TfL's cynemon model) here:
https://findingspress.org/article/18226 ... astructure

[Nearholmer]

I don’t know what objective facts or careful estimates might say, but I personally don’t like little sticky-up curbs or flimsy posts as demarcations either, both feel as if they could themselves become the cause of trouble.

Somewhere (France? Brighton? I dunno!) I saw some raised hump things which seemed quite good, only maybe 100mm high and 300mm wide, white, forming a continuous demarcation between a good, wide shared-use path that looked to have been created by widening a pavement, and the carriageway.

Locally we have a section of a good option turned bad, in the form of a full spec crash barrier between road and shared use path. Super you may think, but the form of the posts supporting the barrier is such that if you clipped one as you were cycling it would inflict grievous bodily harm, all sharp edges of press-formed steel sheet so that it’s like cycling past a field of razor blades up to waist height!

[mattheus]

I don’t know what objective facts or careful estimates might say, but I personally don’t like little sticky-up curbs or flimsy posts as demarcations either, both feel as if they could themselves become the cause of trouble.

Somewhere (France? Brighton? I dunno!) I saw some raised hump things which seemed quite good, only maybe 100mm high and 300mm wide, white, forming a continuous demarcation between a good, wide shared-use path that looked to have been created by widening a pavement, and the carriageway.

Locally we have a section of a good option turned bad, in the form of a full spec crash barrier between road and shared use path. Super you may think, but the form of the posts supporting the barrier is such that if you clipped one as you were cycling it would inflict grievous bodily harm, all sharp edges of press-formed steel sheet so that it’s like cycling past a field of razor blades up to waist height!

On balance, I'd take the floppy wands. They're highly visible; if driving, I think I'd be more inclined to instinctively avoid them than a kerb.
And shouldn't hurt if I ride into one - whereas a kerb can easily lead to injury, let alone sharp-edged armco!

[Pete Owens]

Some benefit for light segregation, more for full

Only if you count increasing the risk of collisions at junctions by a factor of 3 a "benefit".

[Pete Owens]

A study in London estimated that advisory paint was indeed more dangerous than nothing at all. Mandatory paint was found to no overall affect.

To see how much worse cycle lanes make conditions for cyclists take a look at:
http://wcc.crankfoot.xyz/report/cycle-lanes.pdf
And the ones in Oxford tend to be narrower than that.

[mjr]

Some benefit for light segregation, more for full

Only if you count increasing the risk of collisions at junctions by a factor of 3 a "benefit".

Surely that risk — if indeed it still exists with current designs and not only the 1980s ones that old estimate relies upon — is included in that study's collected data and so is more than overcome by the other benefits?

Let's rejoice in what we can all agree upon: advisory lanes are generally awful.

[Stevek76]

Some benefit for light segregation, more for full

Only if you count increasing the risk of collisions at junctions by a factor of 3 a "benefit".

No part of that study suggests that any cycling specific infrastructure leads to a factor 3 increase risk at junctions.

[Pete Owens]

Some benefit for light segregation, more for full

Only if you count increasing the risk of collisions at junctions by a factor of 3 a "benefit".

Surely that risk — if indeed it still exists with current designs and not only the 1980s ones that old estimate relies upon — is included in that study's collected data and so is more than overcome by the other benefits?

The increase risk which most certainly exists and has been known and well understood long before the 1980s - it was the reason that our parliament in the 1930s (being rather more rational and somewhat less authoritarian than those on the continent at the time) refused to legislate for their use to be compulsory - much to the chagrin of the highway planners who have always wanted us off the roads to keep the motor traffic flowing.

And the danger is not a feature of it is down to minor design details - they found the same over many years and in different countries.
It is due to the fundamental geometry of sending conflicting streams of traffic across each others paths:

Any traffic engineer would be sacked for implementing the obviously dangerous lane markings on the left, yet they have spent decades (ever since they failed to make their use compulsory) trying to persuade us that the identical situation on the right is somehow for our benefit.

And they have tried many design tweaks to try to mitigate the danger - whether that is bending the cycleway towards the carriageway, bending away from the carriageway, or merging with the carriageway on the approach, cyclist dismount signs and so on. The one design feature that DOES have a serious impact on safety is that contraflow cycleways are very much more dangerous that with flow ones - so the risk is increased by a factor of 10 rather than a factor of 3.

and so is more than overcome by the other benefits?

As a cyclist I tend to put a greater priority the safety of cyclists than facilitating the free flow of motor traffic - which is and always has been the purpose of segregation.

Let's rejoice in what we can all agree upon: advisory lanes are generally awful.

Indeed. so let us agree simply agree to campaign to remove them, rather than adding even more hazards such as posts cluttering up what is already a restrictive narrow space.

[mjr]

Any traffic engineer would be sacked for implementing the obviously dangerous lane markings on the left, yet they have spent decades (ever since they failed to make their use compulsory) trying to persuade us that the identical situation on the right is somehow for our benefit.

People keep posting that image and ignoring the reply: whether it is safe or not depends on the lights or controls of the junction ahead.

Fundamentally, directing conflicting streams of traffic across one another is exactly what highways designers do at most junctions... and with some of the nonsense that I've seen built, I doubt that a traffic engineer building an approved-but-lethally-flawed layout would get even a minor reprimand in some counties. Hell, how many people do you think were sacked for those 1990s 70mph dual carriageway shoulder lanes that cross slip roads blind? I suspect no traffic engineers and designers have been sacked for cyclist-killing layouts in the last 40 years.

and so is more than overcome by the other benefits?

As a cyclist I tend to put a greater priority the safety of cyclists than facilitating the free flow of motor traffic - which is and always has been the purpose of segregation.

Nice way to avoid the question. So I guess you also see that the data says they are less injurious overall, even if you're right about the junctions.

Let's rejoice in what we can all agree upon: advisory lanes are generally awful.

Indeed. so let us agree simply agree to campaign to remove them, rather than adding even more hazards such as posts cluttering up what is already a restrictive narrow space.

No, because that would give the space back to motoring domination and drive most cycling off those roads. It would be much better to widen and protect the lanes, but some might be OK if motorists are slowed to 20mph and encouraged to use other routes.

[Stevek76]

I repeat, since it was missed or ignored. The factor 3 in the study refers to the presence of intersections of any kind. They did not look at differentiating the various types of unprotected, semi protected and fully protected junctions. I severely doubt there would be enough data to draw any sort of statistically robust on the matter when it comes to london.

If we hop over to the netherlands where they've been observing and reacting to this for decades now. There has been transition to junctions that are fully protected (i.e. time and space) and older designs that rely upon e.g. right turning (our left) drivers yielding to ahead bound cyclists phased out. They have, of course, continued to throttle down on the motor vehicle in urban areas generally with signal timings favouring cycles and pedestrians, streets filtered, parking removed and so on.

It would be much better to widen and protect the lanes, but some might be OK if motorists are slowed to 20mph and encouraged to use other routes.

Not so sure on that, I'd rather painted stuff was consigned to the bin entirely. Either you filter the road such that the motor vehicle demand is low enough that they become effective guests or routes are fully protected. The wide paint seen in some places in NL that these 'quickways' seem partly inspired by (though badly, in dutch equivalents these marked lanes tend to be 2.5m + wide, even if that leaves the central part of the carriagway narrower than a single motor vehicle) are falling out of favour from what I gather in much the way that the older junction designs are.

[Pete Owens]

Any traffic engineer would be sacked for implementing the obviously dangerous lane markings on the left, yet they have spent decades (ever since they failed to make their use compulsory) trying to persuade us that the identical situation on the right is somehow for our benefit.

People keep posting that image and ignoring the reply: whether it is safe or not depends on the lights or controls of the junction ahead.

A simple priority junction - ie the vast majority of junctions on the road network.

Yes, it is possible (though rare) for the minority of junctions that are signal controlled to provide a separate stage for a the cycleway - and indeed this would be universal rather than rare if highway engineers considered cycles to be legitimate traffic; they would undoubtedly do it if there were two parallel streams of motors crossing through a junction. It is also possible with grade separation. But, back in the real world, until every single side street and driveway is equipped with a subway or set of traffic lights - and those lights are provided with a separate signal stage for the cycleway then the danger will remain.

[Pete Owens]

If we hop over to the netherlands where they've been observing and reacting to this for decades now. There has been transition to junctions that are fully protected (i.e. time and space) and older designs that rely upon e.g. right turning (our left) drivers yielding to ahead bound cyclists phased out.

Actually roundabouts are now the preferred junction arrangement in the NL since they have proved to be safer. And cycleways now give way to the carriageway, because giving the cycleway priority doubles the collision risk.

[Pete Owens]

I'd rather painted stuff was consigned to the bin entirely.

Which brings us back to the topic under discussion - because that is what the Oxford quickways are.

Probably the easiest way to quickly improve conditions for cyclists in Oxford would be to paint out their entire network of painted cycle lanes - there are a lot of them and they are particularly poor.

[mjr]

Any traffic engineer would be sacked for implementing the obviously dangerous lane markings on the left, yet they have spent decades (ever since they failed to make their use compulsory) trying to persuade us that the identical situation on the right is somehow for our benefit.

People keep posting that image and ignoring the reply: whether it is safe or not depends on the lights or controls of the junction ahead.

A simple priority junction - ie the vast majority of junctions on the road network.

Yes, but which priority? This is like getting blood out of a stone.

Of course, the vast majority of junctions on the road don't have such marked lanes and (as clarified in January's highway code update) turning traffic is normally expected to give way when turning into them.

Yes, it is possible (though rare) for the minority of junctions that are signal controlled to provide a separate stage for a the cycleway - and indeed this would be universal rather than rare if highway engineers considered cycles to be legitimate traffic; they would undoubtedly do it if there were two parallel streams of motors crossing through a junction.

Ah, congratulations, you've remembered to put "parallel" in this time to exclude the huge number of traffic lights where motorists are expected to give way when turning right even on a green light.

And the separate stage for the cycleway is now the norm. It just takes time to slap the refuseniks into doing it.

But, back in the real world, until every single side street and driveway is equipped with a subway or set of traffic lights - and those lights are provided with a separate signal stage for the cycleway then the danger will remain.

Side streets and driveways don't have road markings like the above implying that the left turn is available.

[...] And cycleways now give way to the carriageway, because giving the cycleway priority doubles the collision risk.

But it's largely immaterial because you can usually judge your arrival for a gap in the motor traffic and if you don't, the vast majority of motorists will give way anyway because of some mix of cyclists being respected as valid transport, the motorist's way ahead being blocked by other motorists anyway and other factors.

Probably the easiest way to quickly improve conditions for cyclists in Oxford would be to paint out their entire network of painted cycle lanes - there are a lot of them and they are particularly poor.

Only if you think turning a lot of cyclists back into motorists and discouraging others from starting cycling is an improvement in their conditions!

The paint-only lanes should go, narrow advisory ones first, but to be replaced with decent spaces for cycling, of whatever type. Just burning the paint off and letting the streets revert to a motoring hellscape is an awful idea.

[Pete Owens]

People keep posting that image and ignoring the reply: whether it is safe or not depends on the lights or controls of the junction ahead.

A simple priority junction - ie the vast majority of junctions on the road network.

Yes, but which priority? This is like getting blood out of a stone.

The danger is caused by parallel streams of traffic crossing each other through a junction - whatever priority rules apply.

Whether the stream approaching in the right hand lane and heading to the left has priority or whether the stream approaching in the left hand lane and heading right has priority it is dangerous, because you put road users in the position of having to give way to traffic coming from behind.

If you still fail to grasp this why not post the image on the left to a motoring forum as a suggestion for an improved lane arrangement for motorway junctions - and report back to us if anyone posts back a reply along the lines of "what a good idea, why has no one ever thought of that".