Cycle Lanes - Question re: markings

fiachs

I was just wondering if I could get some cyclist's opinions on this idea - I'm currently doing research for my undergraduate thesis regarding Traffic Control in Dublin (don't all jump on me at once :P ) and I was thinking about recommending the use of Raised Rib Marking's at the edge of mandatory cycle lanes.

"Raised rib markings consist of a continuous line marking with ribs across the line at regular intervals. Their objective is to increase visual awareness of the carriageway edge in wet conditions or at night, in addition, the markings provide and audible and vibratory warning to vehicles that are straying from the carriageway. When used on all-purpose roads, as opposed to motorways, the rib should be no more then 6mm and they should not be spaced more closer together then at 250mm intervals so as not to create problems for bicyclists or motorcyclists. (Traffic Advisory Unit, 1995)

Here's the pdf - http://www.dft.gov.uk/stellent/groups/dft_roads/documents/pdf/dft_roads_pdf_504747.pdf

I'd just like to get some opinions as to if people think that this would be a good idea or not. I think it'd raise people's awareness of when they're crossing into a cycle lane - too many people do it without thinking!

Downtime

Are they slippery when wet? If they are this would be a concern

fiachs

Downtime wrote:

Are they slippery when wet? If they are this would be a concern

Same as an other markings really. Extensive trials were carried out by the Transport Research Laboratory in the UK. They were originally used on Motorways to make sure that people would still notice the edge of the carriageway in wet or dark conditions. The trials determined that the Rib Markings hadn't and wouldn't contribute to any accidents. Even so, the maximum height was reduced and spacing increased to insure that cyclists wouldn't encounter problems.

gibo_ie

just a quick question RE Cycle lanes and using the raised ribs; i believe where there is a separate area *dedicated* to the use of cyclists it is a great idea, but as far as i can see in dublin, a lot of the marked cycle lanes take up a percentage of one lane of the road, therefore implying to me the driver that this is shared and if there is a cyclist in it to not obstruct it but if there is not it is to be considered part of the driving lane.
Please dont all jump at me for saying this as it is more a question than a statement. Especially when you pull up at red lights and you are covering part of the cycle lane as the driving lane is not wide enough to safely stop within without blocking the cycle lane.

I only say this as some git kicked my car as i stopped in this at lights one day on the howth road.

Another thing and maybe slightly off topic but relevant all the same, why is there a large cyclist *parking* area in front of cars at a lot of traffic lights. I dont believe it is a safe thing to have cyclists pull up in front of traffic at lights as they cant possibly take off quicker than cars/trucks and therefore causing obstructions and possibly accidents at junctions?

Maybe in your thesis you can look at having a wider space at the front left portion of lanes at lights for cyclists to park in while waiting for light change (not that some even bother stopping at lights.. but thats another story:) )

good luck

John_C

If a car's wheel is on the marking it's probably already drifted too far. Would placing the ribs (painted black) about a foot into the traffick lane be better?

fiachs

erm no I'm submitting next week so I'm not changing the entire perspective of the report :P

Why shouldn't the cyclists be able to go ahead of the drivers? (I really don't want this thread going off topic but...) The advanced stop line for cyclists (which I find most drivers ignore) is a safety thing in order to allow cyclists to not be squashed by traffic and to allow them to change lanes at the lights (for right-turns etc)

I specified the manditory cycle lanes for the use of ribbed markings because I I know the majority of cycle lanes are shared space and they're token gestures. The council doesn't want to take space from cars but they're under pressure from the EU to have a certain number of km of "cycle lanes"

I'd like this not to turn into a rant about the deficiencies of cycle lanes - just like to get the general feeling out there about the idea of using these markings

fiachs

John_C wrote:

If a car's wheel is on the marking it's probably already drifted too far. Would placing the ribs (painted black) about a foot into the traffick lane be better?

Painted Black?! Therse are meant as road markings and you couldn't be doing that with them. If a car's wheel is on the markings then they would act as an alert to the driver to stop going any further into the lane.

fiachs

gibo_ie wrote:

a lot of the marked cycle lanes take up a percentage of one lane of the road, therefore implying to me the driver that this is shared and if there is a cyclist in it to not obstruct it but if there is not it is to be considered part of the driving lane.

oh yeah regarding the above. Where there is an unbroken white line on the outside of the cycle lane then it's a manditory cycle lane and vehicles are not allowed drive inside except to access parking or an entrance on the otherside of the lane (I think there's one or two other allowances as well, not 100%)

Where there is a broken white line the cycle lane isn't really a cycle lane and drivers can be in it. Waste of space really!

Mucco

fiachs wrote:

Downtime wrote:

Are they slippery when wet? If they are this would be a concern.

Same as an other markings really.

So they are slippery when wet and bumpy, just what we need.

John_C

fiachs wrote:

Painted Black?! Therse are meant as road markings and you couldn't be doing that with them. If a car's wheel is on the markings then they would act as an alert to the driver to stop going any further into the lane.

Is there any particular reason why the visual warning has to be coincident with the 'audible and vibratory warning'? They serve a slightly different purpose, one marks the edge of the lane and the other marks the edge of where the tyre should be, which is about a foot in from the edge of the lane.

gjim

why is there a large cyclist *parking* area in front of cars at a lot of traffic lights.

The safest place a cyclist can be is directly in front of the traffic. I drive too, so I understand both perspectives. A driver's focus is mainly to the front. The one accident and all the near accidents I've been involved in while on a bike have involved cars IN FRONT of me; for example cars turning left without checking their left mirror, cars pulling out into a stream of traffic from a minor road, vehicles drifting into you pushing you onto the curb, etc. I can understand why this happens as a driver - it's much harder to notice a cyclist behind or to the side of you. I will always cycle as far forward as I can while waiting for a light to change at a junction to allow drivers to see me. This is especially important for right turns and in fact is often the only way to safely do a right turn on a bike.

I will often do this even if I am technically doing something illegal (by being too far forward at the junction) because I value my life and feel I have a better understanding - through direct experience - of the dynamics of cyling than the people who design most of the cycle lanes in Dublin.

robfitz

A rib height of 6 mm seems too high to me and on top of a 2 mm or so white line, it is too high. I sometimes find cycling along on the broken white line annoying which would only be about 1 or 2 mm. Even the way they lay down the red dash and role the tarmac can cause annoyance.

What speeds where the cyclist tests carried out at? 15, 30, 45 or 60 km/h?


The disance this line is from the kerb is also critically important. A cyclist is about 60-70 cm wide and a good cyclist will normaly cycle at or more then 60 cm from the kerb. Also when crossing a 6 to 8+ mm ribbed line like that a cyclist would need to cross the line at about 30 degrees (maybe more) to avoid the front or rear wheel being deflected by a rib.

I would say a cycle track needs to be at the very least 1.5 meters to allow for resonably careful overtaking of other cyclists, 2 meters would be better.

What would be the minimum distance from the kerb (or usable road surface)?


Motorised vehicles sweep debris out towards the side of the road which can then accumulate on the cycle track. Motorised vechicles which the drive near or along the cycle track when there are no cyclists help to keep the cycle track near the line clear of debris. Like here and here.

What effect does a ribbed line have on the accumulation of debris on a cycle track?


I don't think the problem of motorised vechicles driving on cycle track is that big of a problem. The main problem is that motorists aren't aware of how to interact with cyclists and cyclists aren't aware of how to interact with motorists safely. What is needed is lots of education, lots of enforcement and some engineering, but we've been getting the opposite, very little eduction, very little enforcement and lots of engineering.

Take for example on roadway cycle tracks. A line is drawn about 1+ meters out from the edge of the roadway this is to give some guaranteed space to the cyclist, but what happens is that motorists overtake closer, at higher speeds and without indicating because the cyclist is in a different lane and must only need that much space (sic). Warrington Cycle Campaign did a study on the overtaking distance given to cyclist with and without on roadway cycle tracks.
* * * * *

Off roadway cycle tracks tend not to be any better. The cyclist is happily cycling along avoiding the bumps, parked cars, road signs, bins, pedestrians, etc. away from the motorised vechicles. Until he/she comes to a junction and gets lumped back on to the roadway with the motorised vechicles, or is maybe lucky enough to have to wait a few minutes at a Toucan crossings. Even though most accidents happen at juctions.
* * * * *

What problem will these ribben lines solve?


Give an engineer a problem to solve and they'll come up with an engineered solution. I'm not even sure there is problem.

cyclopath2001

robfitz wrote:

I don't think the problem of motorised vechicles driving on cycle track is that big of a problem.

It is if the vehicle is wider than the lane & gets stuck. I was stopped 20 minutes in the rain recently because a guy in a 40 foot articulated lorry got stuck trying to drive down a 1.5 metre wide cycle track. There was no safe or legal way to get past.

The law may permit motorists to drive in cycle lanes but I'm not sure if it allows for them to stop & cause obstruction. Unfortunately, there was no Garda available at the scene to discuss this point.

No amount of paint or raised marking is going to change the fact that some motorists drive selfishly and will deliberately ignore the needs of others.

gibo_ie

fiachs wrote:

oh yeah regarding the above. Where there is an unbroken white line on the outside of the cycle lane then it's a manditory cycle lane and vehicles are not allowed drive inside except to access parking or an entrance on the otherside of the lane (I think there's one or two other allowances as well, not 100%)

Where there is a broken white line the cycle lane isn't really a cycle lane and drivers can be in it. Waste of space really!

Well that is logical and clears it up thanks!

rubadub

Cars in cycle lanes have never been a problem for me (i.e. I hate them but I have never nearly had a accident due to them), I have had several close calls with pedestrians in cycle lanes though. Totally oblivious wandering onto them, or while on them just walking all over the place rather than sticking to one side.