In so far as there is any cycling infrastructure in Oxford it is substandard, but some of it is so bad it is actually dangerous and should be removed. (In some cases its presence also obscures the need for proper infrastructure and better road design.)
Here are a few examples, with suggested solutions (starting with the better ones and moving towards easier but less effective ones). If you have any suggestions for additions to this page, add them in the comments, or email me and I will add them to this page.
The door-lane cycle lanes on Warneford Lane
As well as being in the door zone, these lanes are impossibly narrow. Given the narrowness of the parking spaces, even reasonably well parked large vehicles can protrude 20-30cm into them, giving them an effective width close to zero, if not actually negative. The marked "lane" is about 1m wide, but IAN 195/196, Cycling and the Strategic Road Network gives the recommended width for a cycle lane here as 2m (assuming peak hour cycle flow is less than 150/hour), with a 1.5m absolute minimum, and requires an extra 0.5m if there is a vertical obstruction higher than 60cm adjoining the lane. This is also a very busy section of road — I would guess around 6000 motor vehicles a day, including some buses — so cycling along it in peak hour can involve half a dozen close passes.
Cycling in the main carriageway is much safer here but, because of the huge median separation, drivers tend to speed (as Graham comments below, the speed limit is 20mph, but 30mph is common) and some get angry at being slowed to even 15mph. The marked cycle lanes encourage them to "push" cyclists to the side.
Solution 1: Remove the car parking, put in physically separated cycle paths. (Would need reworking of the roundabout and junction at either end to make those really useful, but it would be a start on making cycling here possible for anyone who can ride a bicycle.)
Solution 2: Remove the "cycle lane" markings, put bicycle symbols in the middle of the carriageway and signpost the whole section "narrow road, do not overtake bicycles".
Solution 3: Remove the painted cycle lanes and do nothing else.
The northbound cycle lanes on Longwall St
Going north on Longwall St, the cycle lanes are both too narrow and appear and disappear abruptly. They push cyclists away from the centre of the lane and thus encourage motorists to overtake just as the road approaches a blind corner, which is dangerous for everyone concerned.
Solution 1: Block Longwall St to all motor traffic (except emergency vehicles). At its narrowest, it's just wide enough to fit proper cycle paths and proper footpaths.
Solution 2: Make Longwall St one-way for motor-traffic. A protected contra-flow bicycle path could then fit in the narrowest section, along with adequate footpaths and a shared motor-vehicle-bicycle lane (marked "do not overtake bicycles").
Solution 3: Mark the entire narrow section of Longwall "Do not overtake bicycles" and put bicycle symbols all over the carriageway. (And, if it ever becomes allowable, drop the speed limit to 15mph.)
Solution 4: Remove the northbound section of painted cycle lane and do nothing else.
Note: I've added an extra "Solution" to both my examples, that being to remove the painted cycle lanes and do nothing else. Which is really my criterion for "so bad it should simply be removed".
Agreed - both roads terrible - I actually go up and down Headington Hill instead of using Warneford. Incidentally the lanes on Headington Hill are terrible as well - make the wide footpath shared use instead or at least clean the bike lanes - daren't use them in damp weather so ride down the middle of the traffic lane instead.
Lanes most of the way through Headington to the park and ride are terrible as well until you reach the ring road and the only decent infrastructure in the whole city!
These roads are indeed bad and another similar case is Donnington Bridge Road. Worse however is Barns Road between BBL and Cowley. The best bits are parts like Warneford Lane, but there sections where the cycle path is separated from the main carriageway. Sounds good, but still the residents park in it and you can't see if the car is blocking your exit (so you'll need to move into the main carriageway before you get there) until you're practically at the entrance to the separated section. EG You're heading towards Cowley here: https://goo.gl/maps/1EiWJpGGLqv - is that white car blocking the cycle lane or not? Now turn the Street View left to look behind you and see the bus that would have squashed you because you made the wrong choice.
Good piece, thank you. I use both roads on a bike and in a car, and the layout doesn't work for anyone.
The narrow part of St Clements at the Plain is also particularly bad, though none of St Clements is particularly good. And the layout of parking on Morrell Avenue may be intended to slow cars down, but more often seems to encourage unsafe overtaking at the squeeze points. There must be a way that we could get proper cycle lanes onto the road there.
Danny didn’t mention (but it’s almost invisible so why should he?) that all these roads are supposedly 20 mph limit. Warneford could be slightly improved if the markings ‘forced’ drivers against the median kerb. But the surface design does the opposite, keeping drivers a metre away. G
Another option for Warneford Lane is to put the car parking in the middle, next to the grassy median, have a wide cycle lane on the outsides. Then it will be cars in the dooring zone, not people on bikes.
(and that of course is why it won't happen - people getting out of cars are considered, subconsciously of course, to be worth more protection, as car users and pedestrians, than people on bikes)
I agree about BBL-Cowley (Barns Road). Much of this area is otherwise a black hole for cycle infrastructure, i.e. there isn't any!
Traffic calming, as implemented, also often works against cyclists, e.g. on Rymers Lane, where the narrowings lack cycle by-passes, and motorists often push through the narrow area as cyclists are riding through.