IAN195/16 is dead, long live CD195.

[gaz]

Don't worry, it's just gone from it's status as an Interim Advice Note to being a full part of DMRB.

Time to update and reference the correct paragraphs and tables in future.

http://www.standardsforhighways.co.uk/h ... ic-web.pdf

[atlas_shrugged]

I had a quick look at CD195 and I found it really poor.

The cycle design specs seem to be sprayed around many different documents. This spec refers to other specs, it is not definitive but sends you on a paper trail.

I did not see anything that specifies how rough a cycle path should be (International Roughness Index). So cyclists using cycle paths are being exposed to Repetitive Strain Injuries.

The design speed for cycle tracks at only 30km/h excludes the use by most road cyclists who will just continue not to use these rough non-continuous, non-direct cycle tracks.

At junctions and road crossings in the UK: toads, horses, cattle, rainbow trout, badgers etc etc have specific infrastructure provided just for them i.e. underpasses, tunnels, bridges. Vulnerable road humans are truly bottom of the heap.

Then there is LTN 0208 which is being upgraded by PJA but cyclists can not have sight of this spec because it is owned by the DfT.

Time to set up a Department for Active Travel.

[Cyril Haearn]

Top speed 30 kmh, that is enough for me
Speed differentials is a big problem, PoBs might be doing 12 kmh or 30+, while in many situations most motors travel about the same speed

I think the solution is duplicating cycle lanes, one for PoBs, one for speedy gonzaleses. And e-bikes
(I am a PoB )

[gaz]

... The cycle design specs seem to be sprayed around many different documents. This spec refers to other specs, it is not definitive but sends you on a paper trail. ...

That's true but it is far from unique to cycle design.

... I did not see anything that specifies how rough a cycle path should be (International Roughness Index). ...

If you follow the paper trail that you mention you'll eventually arrive at CD239. Potholed gravel tracks should not form part of any new cycling provision related to the Strategic Road Network.

To my mind the greatest weaknesses of CD195 are that it is only applicable to new build SRN and that it contains a "get out clause" allowing new build SRN to be designed to lower "shared use" standards.

[mjr]

To my mind the greatest weaknesses of CD195 are that it is only applicable to new build SRN and that it contains a "get out clause" allowing new build SRN to be designed to lower "shared use" standards.

How's that worded, please? (I'll read it eventually but I'm currently wading through two other consultations in my so-called spare time.)

On the design speed, 30km/h is OK if it's the minimum used for things like corners, slopes and visibility splays. I've caught councils using 15km/h in the past, which frustrates most cycling and should be banned IMO.

[gaz]

How's that worded, please?

Scope.png

AIUI "shared use" is deemed appropriate when pedestrian usage is "low".

[Pete Owens]

It is just segregation, segregation and more segregation - and nothing on how to design carriageways to include cyclists needs.

[atlas_shrugged]

@gaz
> If you follow the paper trail that you mention you'll eventually arrive at CD239. Potholed gravel tracks should not form part of any new cycling provision related to the Strategic Road Network.

Nope CD239 does not cut it as it has no specification for how rough a cycle track should be (worst case).

IRI is an international measurement of roughness and is not specified by CD239. As a scientist I like to measure things. If I want to measure voltage I use a voltmeter. Similarly if I want to measure the roughness of a cycle path then an internationally recognised unit to do this is handy. Hence IRI. IRI is a scientific measurement which is a bit like measurement for noise in the audio world.

A major issue we have with our terrible cycle paths in the UK is that road cyclists will not use them. I know their reasons because I make a habit of catching them and asking their reasons. Major reasons reported are:

Cycle tracks are very rough
Cycle tracks are very indirect and your have to keep stopping
Cycle tracks are not maintained (weeds and broken glass)
Cycle tracks are blocked by dog walkers and side by side pedestrians
etc etc

Cycle tracks are good but they must be done to a high specification otherwise the money is wasted.

[gaz]

Nope CD239 does not cut it as it has no specification for how rough a cycle track should be (worst case).

IRI is an international measurement of roughness and is not specified by CD239. As a scientist I like to measure things. If I want to measure voltage I use a voltmeter. Similarly if I want to measure the roughness of a cycle path then an internationally recognised unit to do this is handy. Hence IRI. IRI is a scientific measurement which is a bit like measurement for noise in the audio world.

Fair comment and thanks for the extra info on IRI. I'm reminded of substantial rebuilding of an asphalt cycletrack nearby some four or five years ago.

It went from a smoothish asphalt surface (albeit one with wheel-swallowing longitudinal chasms) to a bumpy asphalt surface because the rebuilt surface wasn't machine layed.

It's failing again and there may be some opportunity to influence the latest proposals for reinstatement. What IRI measure is acceptable for a cycletrack?

[atlas_shrugged]

Hi Gaz

I have the below figure in a spec I wrote for cycle design. I am not an expert - just a cycle track user. So this was a best go at coming up with a figure for the spec. PM if you want me to email a PDF copy of the spec I would be happy to send it to you and work on any suggestions.


International Roughness Index (IRI) less than 2.0, same or better than A-road specification. Tactile paving is
not recommended as not meeting the IRI spec. Rumble strips, raised kerbs are also not recommended for
the same reason.

[mjr]

I think someone told me this had been downgraded recently but I can't find the link now. Does it ring any bells with anyone?

[gaz]

Updated March 2020.

If you use an old link you'll get to a copy marked withdrawn.

The re-issued version is here.

I do not know whether anything substantive has changed.