Bicycle Network: Good Design Guides

Bike riders use roads as direct routes to travel to their destinations - to visit friends, travel to work or school or to go shopping.

Cycling Aspects of Austroads Guides gives the guidelines for providing for bike riding on or along roads (see figure below).  VicRoads cyclenotes No. 7 provides guidance on provision of cycle facilities. The May 2012 paper by the US Mineta Transport Institute - Low Stress Bicycling Network Connectivity provides an excellent model based on San Jose on how lower "stress" places to ride suit a wider range of people and how connectivity to destinations is limited by a person's access to these lower stress cycling environments.

Separating vs Mixing - Speed and volume of traffic

As the speed and volume of motor vehicles on a road increase then more separation is needed for bike riders - see figure below from the Cycling Aspects of the Austroads Guides (note that speeds are actual, not posted speed limits). The faster and busier the traffic, the more separation needed for bikes.

On local streets with low speeds (less than 40km/h) and little traffic (less than 3000 vehicles per day) bikes may not need a separate marked space. As speed  and volume of motor vehicles (up to 60k/h for moderate traffic) increase, more separation is required in the form of marked bike lanes. At higher speeds and volumes separated off-road bike paths are needed.

Figure 2.1 from Cycling Aspects of Austroads Guides showing recommended separation of cyclists and motor vehicles for the speed and volume of motor vehicles on a road. There is a bias towards providing for adult commuter riders. The figure is derived and adapted from European guidelines and may need updating.	Less confident adults, family groups and children require more separation than confident adult commuter riders. The same diagram can be redrawn showing the recommend separation required to enable "normal" people to ride including family groups and children.

Apart from the speed and volume of motor vehicle traffic, the following should also be taken into account when deciding how to provide for bicycles on or along a road corridor: 

• the type of potential bike rider (e.g. school age children, family groups, adult commuter riders);
• the amount and turnover of on-street parking and land use (e.g. shopping strip, school, residential, parkland);
• the make-up of motor vehicle traffic (e.g. cars, trucks, buses).

For instance, collector roads (which connect local streets to arterial/main roads) often have schools, shops and community facilities and will usually carry buses. Given the use by children and the potential conflicts with bus operations, off-road paths may be more appropriate than on-road lanes on these roads. This is despite the Austroads figure at right suggesting on-road bicycle lanes for the expected speed and volume of traffic.

Other bicycle design guides, such as the widely referenced Dutch guidelines (see sidebar at right) recommend more separation at lower motor vehicles speeds (30km/h). This a prudent approach given that less confident riders, including children, can be intimidated by faster moving motor vehicles. The same is true for people walking.

Many potential riders cannot or will not ride amongst or next to fast moving motor vehicles or busy traffic. Whilst painted bike lanes suit some adult riders, usually the more confident (i.e. usually men) riders, they do not suit children, family groups or less confident riders (i.e. usually women). Separated bike lanes, quiet local streets and off-road paths suit a wider range of potential riders and allow a wider cross-section of the community to rider.

This is illustrated in Roger Geller's categorisation of the types of transport rider (below) and also in the VicRoads diagram of network and audience. The "strong and fearless" will ride in all types of traffic conditions and are confident riding amongst motor vehicles. They represent the small percentage of riders who do not need separation from traffic. The "enthused and confident" rider will tolerate some riding in quieter traffic but favours some separation such as on-road bike lanes. They will also use off road paths. These are the types of riders we see in Melbourne's inner areas (and also Portland, Vancouver and London) - they are mostly male adults riding to work. Providing bike lanes and some separation on busy roads allows up to 10% of people to ride. In some areas of inner Melbourne the mode share for trips to work on our roads is at or about this number. In Portland, Melbourne and London the proportion of female riders using a network of mostly on-road lanes with limited separation from traffic is about 20% of riders.

As more separation from traffic is provided with wider bike lanes, reinforced bike lanes and separated bike lanes; and the continuity and comprehensiveness of the bike network is improved, you start to see more "normal" people riding. This is Roger Geller's "interested and concerned" riders who want to ride but need to feel safer and more comfortable than the more confident riders. They need more separation from busy traffic. In Melbourne we are starting to see the proportions of female riders increase as the network of bicycle facilities improves and expands in the inner north of the city. Here almost 25% of people ride to work including a much larger proportion of female riders (up to 40%). The same proportion of female participation occurs in some areas of Montreal and Portland. 

In areas like Copenhagen, Berlin, Amsterdam where there is a comprehensive network and bike are fully separated from fast moving traffic 30-50% of trips are by bike and many more females and children ride bikes (more than 50% in Copenhagen). They are converting the "no way, no how" to riding.

For all types of bicycle facilities, be it marked on-road bike lanes or separate off-road paths, the designs of cross-overs (driveways etc) and intersections are critical elements that need specific consideration. Continuity across intersections is essential if the facility is to be considered a continuous route as opposed to a series of individual sections ending at each street crossing. Just like a water supply network we would not lay individual pieces of pipe and expect them to carry water if they were not connected at junctions. We should not build individual section of bike path or lane without making sure they are continuous and connected at junctions.

All new freeways, main roads and collector roads should be constructed with off-road paths or marked bike lanes. Planners and traffic engineers should err on the side of more separation rather than less for these types of new roads as they suit more potential riders. We believe the line of separation should be shifted so that off-road paths and bike lanes are provided at lower traffic speeds and volumes (see adjusted figure at right and our page on-road bike lanes - off-road paths are separated lanes should be provided in zone 1 and on-road bike lanes in area 2).

	Quiet local streets with low motor vehicle traffic speeds and volumes (less than 40km/h; less than 3000vpd) can be shared by bike and cars with no separate lanes ("mixed traffic"). "Bike boulevards" can run along these roads which are no-through for cars. The Dutch only allow mixed traffic on streets with no marked centreline as this allows cyclists to ride to the left side while motor vehicles travel in the middle of the road. When motorists are forced to merge to the left for oncoming car they give way to any bike rider present.
	At higher speeds and volumes (up to 60km/h and 5000 vpd) there are usually designated vehicle lanes marked and painted bike lanes on the road are suitable for most adult riders. Children and family groups need more separation or an off-road path.
	As speeds and volumes increase more separation in needed this can initially be achieved through visual and tactile separation. Again, children and family groups need more separation or an off-road path.
	At higher speeds and volumes, physical separation is needed for most potential bike riders. This type of separated lane suits less confident adult riders.
	Separated off road paths, usually two way and sometimes shared with pedestrians are needed for roads with speeds above 60km/h and and significant traffic. They suit all types of riders.

Retrofitting bicycle space on existing roads should also aim for the specified degree of separation. However there is often competition amongst existing road uses for limited road and roadside space. The design solution should aim for the optimum degree of separation possible. Often existing uses can be shifted or, in some cases, removed to make space for bikes. It Can Be Done discusses the various methods for achieving space for bikes on existing roads. It Can Be Done has an emphasis for providing painted on-road bike lanes or off-road paths but the same techniques can be used to find space for separated bike lanes which can require more space than normal painted bike lanes. In some cases the specified separation for bicycles cannot be achieved while retaining space for all existing uses. In these cases a lower degree of separation or space may be reinforced with visible and tactile reinforcements such as vibraline, coloured pavement or even flexible traffic poles.

Where there is inadequate road space for providing bicycle lanes on an existing road, a wide kerbside lane may be all that is possible. The accepted minimum widths of wide kerbside lanes are 4.2m wide on 60 km/h roads and 4.5m wide on 80 km/h roads. When retrofitting bike lanes on existing roads sometimes there is opportunity to install bike lanes instead of wide kerbside lane markings when traffic conditions are suitable. Bike lanes offer a better level of service than wide kerbside lanes. For example the City of Yarra has kerbside bike lanes of 1.2 m next to a travel lane of 3.0 m instead of a 4.2m wide kerbside lane.

In the end we should be looking to provide places where people of all ages, from 8-80 years old, can ride their bikes. On existing streets this may be difficult but on new streets there are less constraints.