UK to get first Dutch-style roundabout in Cambridge

[jervi]

I do wonder about bike facilities in the middle of the road. Left hooks are far too common, whereas motorists tend to be looking for conflicting traffic when they're turning right. Although reducing right turns to signalized locations would likely be required.
It also has the advantage of bidirectional cycleways requiring less space than two one-way cycleways per LTN 1/20, without creating a contraflow lane to the left.

I'm not sure people would feel safe in the centre of the road with traffic on both sides and actually getting to it could be a problem if the road is busy so it could just end up not being used

https://www.google.co.uk/maps/@50.83361 ... 312!8i6656
I can second that. This cycle lane is very sketch. Links two side roads for the NCN Route 20 using a bit of the A270. Heading south there are no entry signs, which actually makes the route illegal to follow. If you look closely enough, you can see Nathan's signal head down the road

[solocle]

I do wonder about bike facilities in the middle of the road. Left hooks are far too common, whereas motorists tend to be looking for conflicting traffic when they're turning right. Although reducing right turns to signalized locations would likely be required.
It also has the advantage of bidirectional cycleways requiring less space than two one-way cycleways per LTN 1/20, without creating a contraflow lane to the left.

I'm not sure people would feel safe in the centre of the road with traffic on both sides and actually getting to it could be a problem if the road is busy so it could just end up not being used

https://www.google.co.uk/maps/@50.83361 ... 312!8i6656
I can second that. This cycle lane is very sketch. Links two side roads for the NCN Route 20 using a bit of the A270. Heading south there are no entry signs, which actually makes the route illegal to follow. If you look closely enough, you can see Nathan's signal head down the road

That's stupidly narrow, though. A 3m wide bidirectional with light/curb segregation would be a completely different proposition.

What's with the phantom give way lines!?

[Debaser]

I do wonder about bike facilities in the middle of the road. Left hooks are far too common, whereas motorists tend to be looking for conflicting traffic when they're turning right. Although reducing right turns to signalized locations would likely be required.

It also has the advantage of bidirectional cycleways requiring less space than two one-way cycleways per LTN 1/20, without creating a contraflow lane to the left.

I've been in a few live lectures as well as webinars with Dutch engineers involved in designing infra for active travel and generally they're aghast at the thought of putting cyclists in the area of a central reserve. As far as the 5 design principles are concerned it probably violates all 5, certainly safety (higher likelihood of a vehicle leaving the carriageway to the centre), directness/cohesion (unless you have crossings provided at every side road) and attractiveness (who wants to be 'trapped' between two streams of motor vehicles?).

[Bryn666]

I do wonder about bike facilities in the middle of the road. Left hooks are far too common, whereas motorists tend to be looking for conflicting traffic when they're turning right. Although reducing right turns to signalized locations would likely be required.

It also has the advantage of bidirectional cycleways requiring less space than two one-way cycleways per LTN 1/20, without creating a contraflow lane to the left.

I've been in a few live lectures as well as webinars with Dutch engineers involved in designing infra for active travel and generally they're aghast at the thought of putting cyclists in the area of a central reserve. As far as the 5 design principles are concerned it probably violates all 5, certainly safety (higher likelihood of a vehicle leaving the carriageway to the centre), directness/cohesion (unless you have crossings provided at every side road) and attractiveness (who wants to be 'trapped' between two streams of motor vehicles?).

The A38 example in Birmingham works to an extent because to get an errant vehicle onto the cycle route there would involve crashing through several trees, but it doesn't reduce the access issues. There are several signal controlled accesses onto it, that said.

[traffic-light-man]

The B5175 Princes Ave in Liverpool is currently getting the central reservation cycle route treatment. From what I can see, there's more signalised junctions than there used to be, I assume in order to facilitate access to the cycle route.

[marconaf]

On your ideal segregated junction, though, how do the cyclists get to the middle?

Are you saying that there should be additional crossings of the circulatory carraigeway to facilitate a right turn from each direction from the left of the roundabout, in addition to the straight ahead crossings? I suspect that would cause far more issues than with the current scheme unless the circulatory cariageway because the driver will be looking right on entering the roundabout, not left - the only solution to that is to make the circulatory carriageway absolutely massive and there isn't space here to do that.

Or are you suggesting that the cyclists should somehow be prioritised to the middle of the road prior to the roundabout to cross the circulatory carriageway more safely? I don't see an obvious way of building that without creating a dangerous blind spot conflict.

As far as I see it, the present design would meet my needs nicely - segregated from cars and pedestrians, safe for children, not having to stop at lights or turn 90 degrees, and if it comes with the additional benefits that is designed to be offputting enough to ensure that any angry leisure or communting cyclists in lycra opt to play with the cars in the road rather than giving you grief for cycling too slowly with a bike full of shopping and a child in tow, then that's just an added advantage in my book!

I dont have the ability to draw it on a mobile, but imagine a crossroad with a circulating area in the centre for ped/bikes and an outer ring gyratory for cars. In effect flipping what is here - so no more land take. Cars would have to stop at each axis as they cross it. Im explaininf it badly - just cant draw a picture!

I like how you characterise people who want to use routes efficiently as “angry lycra leisure/commuter” who naturally give grief to slower cyclists. That’s a really grown up attitude and 100% reality. Ive never worn lycra and Ive never seen any cyclist give another one grief but hey, lets shoehorn that one in eh.

Layouts that add distance are the exact opposite of what we need to do if we want more journeys to be on bike.

There should be a presumption that cyclists (and pedestrians) get the shortest routes. Cars being powered can take the longer one.

Can you imagine having to negotiate multiples of these on say a 3-5mile cycle in a town? It would take forever. That isnt going to encourage people, and it will drive (hah!) away people who do use it if we design everything around a non confident yet somehow children towing and shopping laden niche. Neither of which are even a large minority of actual cylists.

As for the “dont need effussive grateful ... but good enough infra”, thats just yet another recourse to an excuse for laziness. If people hadnt campaigned against the appallingly stupid cycle infra put in place todate (for which they got the exact same lazy response) then it wouldnt now be getting slowly (glacially) better. But still a long way to go and part of that clearly is that planners and designers need to have it set in concrete that you give the cyclists the easiest and fastest option and cars work round that.

[Bryn666]

Your proposal would kill cyclists.

Traffic entering a roundabout and then being presented with a give way between arms for a cycle/footway would have low compliance due to the confusion it would cause. To have any chance of working the roundabout would need an ICD of over 80m so completely impossible to build in any urban area.

If you want a direct cycle route then the answer is a signalised junction. But then people complain they have to wait for a green light.

The Dutch roundabout is a proven compromise that works well where it is employed. Trying to reinvent the wheel is pointless.

[Debaser]

On your ideal segregated junction, though, how do the cyclists get to the middle?

Are you saying that there should be additional crossings of the circulatory carraigeway to facilitate a right turn from each direction from the left of the roundabout, in addition to the straight ahead crossings? I suspect that would cause far more issues than with the current scheme unless the circulatory cariageway because the driver will be looking right on entering the roundabout, not left - the only solution to that is to make the circulatory carriageway absolutely massive and there isn't space here to do that.

Or are you suggesting that the cyclists should somehow be prioritised to the middle of the road prior to the roundabout to cross the circulatory carriageway more safely? I don't see an obvious way of building that without creating a dangerous blind spot conflict.

As far as I see it, the present design would meet my needs nicely - segregated from cars and pedestrians, safe for children, not having to stop at lights or turn 90 degrees, and if it comes with the additional benefits that is designed to be offputting enough to ensure that any angry leisure or communting cyclists in lycra opt to play with the cars in the road rather than giving you grief for cycling too slowly with a bike full of shopping and a child in tow, then that's just an added advantage in my book!

I dont have the ability to draw it on a mobile, but imagine a crossroad with a circulating area in the centre for ped/bikes and an outer ring gyratory for cars. In effect flipping what is here - so no more land take. Cars would have to stop at each axis as they cross it. I'm explaining it badly - just cant draw a picture!

Something like this?

[Bryn666]

That's my interpretation and my comments stand - the ICD would need to be huge to safely accommodate that. With the outer ring for bikes traffic stops one vehicle length away from the roundabout which prevents delays building - under this proposal everyone stops and the roundabout fails to function.

A signalised junction with an all red for cyclists to scramble would be more effective.

[Al__S]

as a local and a cycle campaigner, I should mention that whilst I'm supportive of what's been done here, I do believe that on a road as busy as this the Dutch approach would absolutely be to make it a signalised crossroads. Probably with the acute turns banned, at least on the south side of the junction

[Jim606]

Fendon Rd, roundabout, cycleway on a raised table when it crosses the pedestrian crossing

as a local and a cycle campaigner, I should mention that whilst I'm supportive of what's been done here, I do believe that on a road as busy as this the Dutch approach would absolutely be to make it a signalised crossroads. Probably with the acute turns banned, at least on the south side of the junction

Fully agreed, this is basically the point David Hembrow was making. Another interesting observation comes from another cycle campaigner Mark Treasure from his; https://twitter.com/AsEasyAsRiding/stat ... 3706556416 blog.

He points out that the when the cycleway crosses the pedestrian crossing it is on a raised table, yet the main vehicle carriageway isn't. The tread goes onto say that this may be because of the frequency of bus services along the route?

[Al__S]

I am sort of realistic though, much as this wound up with horrible cost over runs a rebuild to a non-roundabout junction would have been much, much more to begin with

[Keiji]

[...] when the cycleway crosses the pedestrian crossing it is on a raised table, yet the main vehicle carriageway isn't. The tread goes onto say that this may be because of the frequency of bus services along the route?

I'd wondered why the zebra + cycle crossing wasn't guarded from traffic by a speed table, as this would have helped avoid the problem of careless drivers assuming they have priority, not looking, and exiting the roundabout at speed.

If the problem is that buses travel on the route, surely the answer is to use one of those smaller speed cushions (example here) (not sure if there is a specific term for them) which will disrupt a car but not a large vehicle?

Of course, on the exits, such a speed cushion would have to be placed immediately after leaving the circulatory carriageway, before the cycle crossing... but I think it would still work.

[c2R]

With regard to the central approach idea, with cyclists in the middle of the road, the issue was far as I still see it would be in cyclists actually getting to the middle of the road in the first place.

With regard to the speed tables issue on crossings - again, this is on approach to a hospital - not ideal for speed tables on the crossings - although of course the cushions could be used nearby. Not that I think these are particularly effective, given the relative wide wheelbases of most new cars.

[Bryn666]

With regard to the central approach idea, with cyclists in the middle of the road, the issue was far as I still see it would be in cyclists actually getting to the middle of the road in the first place.

With regard to the speed tables issue on crossings - again, this is on approach to a hospital - not ideal for speed tables on the crossings - although of course the cushions could be used nearby. Not that I think these are particularly effective, given the relative wide wheelbases of most new cars.

An alternative would have been to raise the entire roundabout onto a table but that's cost and fill material that could be best spent elsewhere. The geometry of roundabouts should keep speeds down - if it doesn't then it's not working.

[traffic-light-man]

On your ideal segregated junction, though, how do the cyclists get to the middle?

<snip>

I dont have the ability to draw it on a mobile, but imagine a crossroad with a circulating area in the centre for ped/bikes and an outer ring gyratory for cars. In effect flipping what is here - so no more land take. Cars would have to stop at each axis as they cross it. I'm explaining it badly - just cant draw a picture!

Something like this?

I stumbled across this example of an internal roundabout cycle track straddling the Dutch/German border. As Bryn has mentioned, it's fairly large and in actual fact, only one of the cycle tracks actually interface with an adjoining road, the rest being offset from the motorised traffic entry/exit points. In addition, cycles give-way to general traffic on the circulatory.

[c2R]

I stumbled across this example of an internal roundabout cycle track straddling the Dutch/German border. As Bryn has mentioned, it's fairly large and in actual fact, only one of the cycle tracks actually interface with an adjoining road, the rest being offset from the motorised traffic entry/exit points. In addition, cycles give-way to general traffic on the circulatory.

Wow, that's a mess - On entering the roundabout here: https://www.google.com/maps/@52.6462255 ... 312!8i6656 the driver would be looking left, and immediately has an uncontrolled crossing to the right - although the cyclist has to give way.

Given the roundaobut is half and half on the border, why are the two parallel roads not a dual carriageway - the junction could be made a lot safer by marking it as such, rather than having the border sort of do half and half. Particularly given this sort of mad situation, where the office has a car park in a different country, but there's no access to the rest of that country's road network anyway:

https://www.google.com/maps/@52.6475871 ... a=!3m1!1e3

[Keiji]

With regard to the speed tables issue on crossings - again, this is on approach to a hospital - not ideal for speed tables on the crossings - although of course the cushions could be used nearby. Not that I think these are particularly effective, given the relative wide wheelbases of most new cars.

Cushions are still useful I think - even if your car can get all four of its wheels around them so you don't feel a bump at all, you would have to steer into exactly the right position to pull that off - and doing so takes effort and concentration and most likely requires going more slowly - and even if it doesn't require going more slowly, forcing the driver to concentrate on the road more surely also makes them more likely to observe something ahead and able to react to it, for example, a cyclist. Typically if you don't put any effort into going over a speed cushion (especially on a curve), you'll end up with just one wheel going over it, which feels even worse (at least to me it does!) than going over a larger one with all four wheels.

[marconaf]

On your ideal segregated junction, though, how do the cyclists get to the middle?

Are you saying that there should be additional crossings of the circulatory carraigeway to facilitate a right turn from each direction from the left of the roundabout, in addition to the straight ahead crossings? I suspect that would cause far more issues than with the current scheme unless the circulatory cariageway because the driver will be looking right on entering the roundabout, not left - the only solution to that is to make the circulatory carriageway absolutely massive and there isn't space here to do that.

Or are you suggesting that the cyclists should somehow be prioritised to the middle of the road prior to the roundabout to cross the circulatory carriageway more safely? I don't see an obvious way of building that without creating a dangerous blind spot conflict.

As far as I see it, the present design would meet my needs nicely - segregated from cars and pedestrians, safe for children, not having to stop at lights or turn 90 degrees, and if it comes with the additional benefits that is designed to be offputting enough to ensure that any angry leisure or communting cyclists in lycra opt to play with the cars in the road rather than giving you grief for cycling too slowly with a bike full of shopping and a child in tow, then that's just an added advantage in my book!

I dont have the ability to draw it on a mobile, but imagine a crossroad with a circulating area in the centre for ped/bikes and an outer ring gyratory for cars. In effect flipping what is here - so no more land take. Cars would have to stop at each axis as they cross it. I'm explaining it badly - just cant draw a picture!

Something like this?

Wow thats a good drawing.

I’d keep cyclists to the sides - I think putting them in the middle throws everything. Although that doubles car xings.

I guess more like how some junctions go all red with the centre a free for all.

I dont think the take for land would be bigger, just reversing the inner and outer radii.

I really need to get to a laptop!

It’s just an idea - but the concept is give cyclists the direct route, so they use it
as it gives a benefit, and give cars the indirect as they are motorised.

[traffic-light-man]

I'm not sure if the mods might want to hive this off in to another thread, but following on from the central reservation cycleway discussion earlier in this thread, I took a walk down the new the B5175 Princes Ave in Liverpool the other day now that it is open for use.

One end is a roundabout, and perhaps could have done with becoming a dutch-style roundabout. Or perhaps even a cycle and pedestrian hamburger over to the park, or even just a signalised T-junction. But instead, cycles are routed on and off the reservation using a pair of Toucan crossings on to a section of shared use footway with 'no cycling' signs at each end (the same on both sides).

The other end is also a pair of Toucans for access/egress to/from the central cycleway, however a combination of painted/segregated facilities continue towards the city centre as far as AA562 Upper Parliament Street.

The main stretch is pleasant as far as walking down a central reservation goes, but the retention of two traffic lanes still promotes speeding from what I can see. The two intermediate junctions are functionally identical to one another and fully signalised. There is the strange use of give-way lines within the junction too, which I'll discuss in the recent thread regarding in-junction markings.

At the junctions, there's a huge amount of paint all over the place to 'manage' cycle and pedestrian traffic.

The crossing sites are mainly parallel crossings with push buttons, but to access the parallel crossing points from the adjoining roads, cyclists have to leave the carriageway, join a short section of shared use footway and then use a toucan crossing to be on the correct side of the junction to use the parallel facilities.

I have a generous amount of photographs of the whole route (only taken with my phone, mind you), which I can upload somewhere should anyone be interested.