Richard Mann wrote:Now we're getting to the nub of it. You need more space because traffic is going faster, but the standard demands excessive lane-width at all speeds, so everyone is so busy aiming off the standard,
you cannot be serious.
Agreed most places do not treat the standards with quite the same degree of contempt as Oxford - but cases of standard cycle lanes are so rare that they tend to make the national news.
that they don't know when it really is required.
The minimum 2m standard has nothing to do with speed but the basic dimensions of the design vehicle and the need to allow a minimum amount of clearance.
The standard needs to be more realistic
The standard traffic engineer speak meaning we should know our place.
They understand that the one and only purpose of cycle lanes (and other facilities) is to keep us out of the way of important vehicles with motors.
This is why the only place that you will ever see cycle lanes (with very rare exceptions) are on bits of tarmac not used by the main traffic flow - the width is not determined by how much space we need, but by how much spare space they have surplus to requirement.
(and more evidence-based),
OK lets do a bit of evidence basing:
Minimum clearance a cyclist should keep between themselves and a kerb - 0.5m
Dynamic envolope (ie width of a moving cyclist) - 1m (you need to allow more on hills or bennds)
Minimum width needed between a cyclist and another vehicle - 0.5m (This is only rally adequate for cyclist- cyclist clearance on cycle paths - you need to increase this at greater speed)
Add them together and you get a
minimum space requirement of 2m.
Even if you think you are prepared to scrape a bit off the margins, and riding a trike so you can keep a dead straight path, presumably you think it is a good idea for cyclists to perform hand signals without slapping pedestrians or cars.
and much more focused on providing a buffer zone around parking, especially when pulling out into the traffic is impractical.
OK lets to a bit of evidence basing on width needed for a buffer zone.
Car doors swing open by about 1.2m - so the evidence based minimum width required for buffer zone is 1.2m