Saturday, 26 January 2013

Design Problems

Not long ago, in an effort to do something to make life a little easier for people on bicycles, WA Greens Senator Scott Ludlum introduced the Bike Blackspot smartphone app. It works by letting the user report on hazards, including taking pictures, and emailing them to their local responsible authority.

I have used it to send a few reports. One was about one of those 80cm wide bike lanes that is plonked between two lanes of traffic; one often moving while you are stationary. This one was on (and still is) the corner of Angas Street and King William Street:


It's since been painted green but I'm not sure that makes a huge difference.

One of the recipients of emails that the app sends when you make a report is the transport minister, Pat Conlon (or was before the Cabinet reshuffle). I get the feeling he wasn't entirely happy with receiving complaints directly and so he wrote me a letter. It said (among other things):

Unfortunately the App, which was developed by a third party, sends the information collected to my office which delays details being passed on to DPTI or the council responsible for the road, path or trail.

The letter went on to list the things the current State Government has done to improve Adelaide's bike network and the money that has been spent. As to the standard of bike facilities, the letter said:

DPTI is also committed to providing facilities for cyclists as an integral part of all new urban arterial projects and upgrades. All bicycle lanes are installed by DPTI in accordance with the relevant traffic engineering guidelines and standards which can now include vertically or horizontally separated bicycle lanes.

Hearing common complaints about crappy and inadequate bike lanes ending abruptly, among many others, I was interested in finding out what the "guidelines and standards" were that the Minister refers to at the end of his letter.

And so I asked.

I received another friendly response after a few days that said:

When installing bicycle lanes, the Department of Planning, Transport and Infrastructure (DPTI) acts in accordance with relevant traffic engineering guidelines and standards which include:
  • Australian Standards AS1742.2, Manual of Uniform Traffic Control Devices, Part 2 - Traffic Control Devices for General Use
  • Australian Standards AS1742.0, Manual of Uniform Traffic Control Devices, Part 9 - Bicycle Facilities; and
  • the Cycling Aspects of Austroads Guides which contains key information that relates to the planning, design and traffic management of cycling facilities and is sources from several Austroads guide, primarily:
    • the Guide to Road Design;
    • the Guide to Traffic Management; and
    • the Guide to Road Safety.
Of those listed publications, the Cycling Aspects document is probably the most relevant. You can buy a printed copy for $99 or download a pdf copy for nothing. All you need to do is register. You then have access to all of the Austroads documents. The other documents, especially the standards, that the Minister refers to deal primarily with road signs. Based on my experience, this seems to be one of the most popular:

The Cycling Aspects document bears some similarity to the American NACTO design guide. For instance, on page 54 is a fairly typical example of an intersection design that you see in both documents:

It is a lot like the NACTO version that was discussed at some length on the Bicycle Dutch blog together with a short lesson on how to improve it.

In my view, the designs are far from ideal because so many of them have conflict designed into them. For example, this is figure 5.29 on page 80:

Putting aside the fact that the bike depicted is painted on the edge of a freeway, the treatment at the slip lane is a recipe for disaster. You have a combination of high speed vehicles coming off the freeway and the poor lone cyclist hoping for a suitable break in the traffic while craning her neck to the side. It probably generally works for the few people game enough to use it but it would be fairly unforgiving of any error.

Roundabout design seems overall to be fairly horrific (pp 73-78). No real excuse for that. There are plenty of decent examples of how to provide proper protection on roundabouts.

Interestingly, the document does occasionally contemplate genuine half-decent treatments (eg: fig 7.6 on p97) and even with priority for bicycles. This is the suggested design for "low-volume local streets" (fig 7.8 on p99):

You can see the two-way bicycle track has priority over the road and maintains its level through the intersection. I add that I have never seen a crossing like this anywhere.

Generally though the cheap rubbish is used as illustrated by figure 5.3, which shows the standard treatment you see across the country (picture 3(c) helpfully illustrates the built-in conflict with the car crossing the path of the cyclist):

In other words, painted bike lanes (if any) that are routinely ignored by motorists just like the ones I originally complained about to the Minister. And that includes in totally inappropriate spaces. This is on Main North Road, Parafield - 3 lanes each side and a speed limit of 80km/h:

Part of the problem comes with the references to different types of cyclists. The document is littered with references to "experienced" and "less experienced" cyclists. That topic has been discussed at length. If you are serious about these things, routes should be good enough that they can be used by anyone from 8 to 80. You don't need separate treatments for different skill levels, whatever that might mean.

Even if the designation is correct, how do you possibly decide who to cater for? Why is one roundabout aimed at "experienced" cyclists and another aimed at those who are "less experienced"? Do you have two seperate networks? Imagine if we treated motorists that way - two separate types of road for experienced and inexperienced motorists. What a total waste of space and money for one thing. Not only that though, can you imagine the complaints? I think that there are different classes of motorist, ranging from the barely competent to the total moron and I have heard people talking as if driving on a main road is too difficult for them. However, do they need a separate remedial road network? Maybe they do.

For a great commentary on that topic, I would recommend a read of this and this.

A further error that is apparent is what appears to be the decision-making process about which road treatment to use, assuming by some miracle there is a road treatment. Figure 2.1 shows a familiar grid for deciding what type of treatment to use, from mixed traffic to separated paths:

Putting aside the fact that the grid does not even get used (the fact that there are effectively no segregated lanes proves that), I think it is a mistake to use current numbers of cars to determine what type of treatment to use. There are two major problems with that approach. First, you will always be playing catch-up. Once you have allowed the street or road to develop, you then somehow have to engineer the cycling treatment after the event. That will inevitably involve compromise.

Second, both your cycle and car networks will work much better if you designate roads and their uses in advance. Once that is done, it is that designation that determines the treatment that is necessary and that road's place in both networks. Again, smarter people have described this far better than I could; for example, the Cycling Embassy of Great Britain (I recommend a read of what they say).

Austroads could do a lot worse than just go and buy a copy of the CROW manual. I assume that a shift in car use is what governments want. Every State Government has a cycling plan and is forever claiming it wants to reduce car use; primarily because if the cost of excessive car use that ultimately they end up paying. Even the Commonwealth Government has recognised the need for a change and is asking for feedback on active travel. Little treatments after the event though will not help them. However, a complete network whereby the two modes share space on quiet residential streets, that cannot be used for rat-running, and are separated once speeds change significantly will make a difference.

These are the guidelines that most State Government traffic engineering Departments seem to use. An update of them might be a good place to start.

Now who do I write to next?


  1. Thanks Edward. Interesting document. I like the road hump bypass in 4.11. Unley and Burnside Council could do with some of those.


    1. Totally agree. That is what speed bumps should look like.

  2. That was a good read - I haven't checked out the Austroads guide but will seek it out. I'd say though - a good starting point would be a bike design guide from scratch. National would be good however with policy momentum in SA it would be convenient to push for that here. Velo Quebec have a quality bike traffic design guide and there are others. I'm starting to collect as many photos of bad infrastructure in the twittersphere (@notabikelane) if you're on it.

    1. Agreed. They need to re-write the design guide. I'll also check out the Velo Quebec version. Thanks for the tip.