Bicycle Network: Good Design Guides

[updated]

12 October 2012   Austroads has recently published a report "Cycling on Higher Speed Roads" which investigates providing for bikes on sealed roads with speeds over 70km/h. It discusses several techniques to help reduce "inherent conflict" to more acceptable levels: 

• providing an alternative route
• providing space on-road  (lanes or sealed shoulders mid-block and provision at intersections)
• reducing the speed limit
• non-engineering techniques such as technology and information provision.

The report (see link in box on right of page) also recommends appropriate maintenance practices such as sweeping of debris along identified bicycle routes and providing smaller aggregate size surfaces for smoother cycling and additional space for bike riders.

Several improvements or additions to the existing Austroads guides are suggested, including provision of audible tactile linemarking or raised separators to help prevent motor vehicles impinging on the bike riding space.

Note: The wording used here deliberately avoids the use of the words "cyclist" or "motorist" in order to diminish the perception that people riding bikes don’t drive and that people who drive don't ride bikes. We also avoided saying  "training routes" as we recognise that not all people are training for any event. Most people out riding on these routes are motivated  to get fit and stay in touch with others, often in an informal riding group.

This page deals with fitness routes mainly on quieter roads without car parking or traffic lights. These are usually rural roads. Urban (and suburban) on-road fitness routes, such at Route 33 (Beach Rd) usually have kerbs, gutters, parking and lights and lower speed limits.

What's the problem?

People riding on roads to improve their fitness often face road conditions that sometimes put them at risk of collision with motor vehicles travelling at high speeds.

Systematic improvements to established routes, such as sealed shoulders or improving blind corners, reduce the risk of crashes for all road users, not just bike riders. For instance, providing sealed shoulders provides more room for error on the edge of roads before a vehicle looses control on a soft road edge.

Improvements to road design can be combined with better management of the roads and other measures to improve road user behaviour.

What are the risks?

On-road fitness routes often use high speed limit (80-100km/h) roads in rural or urban fringe areas. The example at left shows the popular Great Alpine Rd fitness route near Bright in NW Victoria. Any crash between a bike rider and a motor vehicle travelling at these speeds is potentially fatal and often serious. Bike riders tend to chose low traffic routes which can mean meetings between bike riders and people in motor vehicles are less frequent and thus less expected. Bike riders, in the quest for lower rolling resistance and higher average speeds, tend to choose road bikes with high pressure, narrow tyres. These are more easily deflected by surface defects and uncomfortable to ride on rough road surfaces so bike riders will tend to avoid rough road shoulders when the road itself is smoother due to vehicle traffic compacting the road surface.

The main risks on these roads are:
• Being hit from behind while riding – people in motor vehicles may not be looking for or expecting bike riders and can hit them from behind. Low visibility conditions can contribute, whether it is road conditions (blind corners, overhanging vegetation etc), weather (sun glare, low light especially dusk and dawn when bike riders are more prevalent) or lack of conspicuity on the part of riders (lack of, or inadequate lights or bright clothing). High speed collisions from behind are a major cause of death for bike riders on high speed roads.
• Slipping or hitting an obstacle and falling - bike riders are more sensitive road defects such as loose gravel and potholes. Hitting or loosing control while trying to avoid them can lead to serious crashes due to the relatively high speed of the rider. If the rider veers or falls into the path of a motor vehicle the impact can be fatal.
• Avoiding hazards and being hit by a motor vehicle. To avoid coarse or bumpy road surface, bike riders will tend to rider closer to the centre of the road where the road surface is smoother. Even if shoulders are provided, they can be filled with coarse gravel swept from the road surface by motor vehicle tyre travel or they may be made of a coarse gravel aggregate that is unsuitable for bicycle travel (over 10mm stone size). Bike riders will avoid riding on this surface as it is uncomfortable and unstable. This may cause them to ride where the road is smoother, often on the edge of the wheel track of motor vehicles which have rolled smooth the road surface. The same is true for other road hazards such as potholes or ridges in the road.

What is the solution?

The solution is to pick certain routes and enact measures which are targeted at reducing the risk of crashes.

1. Know the rider(s)
People riding for fitness goals ride longer distances (30-150kms or more), at higher speeds (above 20km/h) on quieter roads, often with other people in a social group (though often alone). The selected routes nearly always start and finish in the same place. Loop routes are preferred (as opposed to out and back routes) as they offer a variety of terrain and views. Longer rides often take in quieter rural or urban fringe roads that may be narrow and/or not have a road shoulder.

Goals for riders are fitness (sometimes training for an event) and socialization (riding with others and being able to talk together which means riding two abreast).
A group of riders can organize themselves into a two column peloton which rotates the leading riders in a clockwise direction so each rider gets takes turns at the front or the group setting the pace (or at the back resting) and each rider meets all the other riders in sequence as the lead rotates. If safe to do so, a rider may change position in the outside column making the group three bike riders wide. This is within the road rules but only if the road ahead is safe for the passing manoeuvre.

2. Consolidate routes
Consult with local riders and decide on a limited number of routes of varying distances. Maximize coincidental sections with other routes and event routes e.g. for organized rides (e.g. GVBR) or races (e.g. world road racing championships). For example the 50km ride and the 120km ride could share the same 20km start before diverging.

3. Audit route and target high risk sections or circumstances
Audit the routes and decide on a prioritized list of solutions that target high risk sections and circumstances. The aim is to have a plan for improvements that bring about a “Steady improvement of high risk sections on designated routes”. The actions will usually be mostly physical improvements but should be supported by management

4, Enact Targetted Improvements

a. Physical measures
Potential road improvements include:

• Sealed shoulders (maybe as part of upgrade of road or particular sections) and extending existing shoulders so they do not end abruptly in high risk areas. Shoulders should be 7mm aggregate and maintained to keep clear of gravel
• Visibility improvements for bike zone– lanes, colour, tactile surfaces
• Reconfigure or adding lanes– e.g. on blind corners to make outer lanes wider or adding lanes for overtaking on hills
• Short off road sections if needed – caution with exit and re-entry so they are smooth and visible and riders able to maintain speed as they will otherwise avoid them. For example on corners or along escarpments
• Seal driveways and road crossing (to reduce gravel ingress)
• Resurfacing rough sections
• Signage (e.g. blue route 50km circuit signs) –in conjunction with road improvements and increase awareness of the possibility of encountering bike riders.

b. Non-physical measures - traffic management
Management measure might include the following. More intensive management might be needed on higher trafficked routes in urban areas.

• Adjustment of speed limits –especially on corners
• Variable message signs
• Time based speed limits (and other measures – e.g. limits on trucks)
• Cleaning of roads especially shoulders and driveway entrances/crossings to make smooth for riders on a more regular basis on the established routes
• Maintenance of road surface especially:
•               - defects on road edge that are critical for bike riders
•               - roadside vegetation that impairs sight lines and usable road width

c. Non-physical measures - road user behaviour
For people in motor vehicles and on bikes. This includes education and enforcement of rules and behaviours

• Impaired driving/ riding – drugs, alcohol, sleep speed, headphones for riders. Targeted enforcement at key times e.g. pre-work, post football matches.
• Leaving room while passing bike riders and slowing down if necessary to pass safely
• Visibility – lights and visible clothing for riders especially in low visibility times and conditions
• Rear view mirrors for riders
• Education for tourists (e.g. marked on maps) and for other different audiences (e.g. delivery drivers)

What do the guidelines say?

There are no specific guidelines relating solely to fitness routes for bike riders on rural roads.  Prioritising treatments, deciding routes, and forming road management and maintenance regimes are all part of the solution and will need the support of road management authorities (local and state) with their own guidelines. The Austroads Guides to Road Design deal with phycical measures such as lane widhs and clerances and guidance on surfaces for bike riders. 

The Austroads Guide to Road Design Part 3: Geometric Design deals with traffic lane widths and shoulders. Full wording of relevant sections is reproduced at right and tables are at bottom of this page.

Lane Widths

The Guide recommends 3.5m as the standard lane width, including on rural roads. This however does not seem to allow space to pass a bike riders safely when there is an oncoming vehicle. The driver would have to brake or accelerate to avoid a dangerous passing:

"4.2.6 Rural Road Widths
The desirable lane width on rural roads is 3.5m. This width allows large vehicles to pass or overtake without either vehicle having to move sideways towards the outer edge of the lane. The lane width and the road surface condition have a substantial influence on the safety and comfort of users of the roadway. In rural applications the additional costs that will be incurred in providing wider lanes will be partially offset by the reduction in long-term shoulder maintenance costs. Narrow lanes result in greater numbers of wheel concentrations in the vicinity of the pavement edge and will also force vehicles to travel laterally close to one another than would normally happen at the design speed. Drivers tend to reduce their travel speed, or shift closer to the lane/road centre (or both) when there is a perception that a fixed hazardous object is too close to the nearside or offside of the vehicle. When there is a perceived fixed hazard, there is a movement by the vehicle towards the opposite lane line. "

"On two lane sealed roads, the total width of seal should desirably be not less than 7.2m to allow adequate width for passing."

Table 4.5 Single carriageway rural road widths notes that  " Where significant numbers of cyclists use the roadway, consideration should be given to fully sealing the shoulders. Suggest use of a maximum size 10mm seal within a 20km radius of towns."

Shoulders

Austroads Part 3A also deals with shoulders. The Guide notes that shoulders provide safety and maintenance benefits as well as a space for bike riders:

"4.3 Shoulders
4.3.1 Function
Road shoulders are provided to carry out two functions: structural and traffic. The structural function of the shoulder is to provide lateral support to the road pavement layers.

The traffic functions of the shoulder are:
• an initial recovery area for any errant vehicle
• a refuge for stopped vehicles on a firm surface at a safe distance from traffic lanes
• a trafficable area for emergency use
• space for cyclists
• clearance to lateral obstructions
• provision of additional width for tracking of large vehicles "

Table 4.7 (at bottom of this page) indicates that a 2.0-3.0m sealed shoulder is required to cater for bike riders. A 2.5m wide shoulder allows cars to safely pull off a road while a 3.0m wide shoulder allows trucks to do the same.

Part 3 (at section 4.8.4 Cross-section and Clearances also states that "On roads carrying less than 3000 vehicles per day, bicycle riders and motor vehicles can generally share the road" and that no separate bicycle facility is needed.  The section also talks about "wind force" and indicates, in Table 4.16 (shown at bottom of this page) the clearances needed from adjacent trucks. Most rural roads would have less than 3000 vehicles per day, so a separate facility may not be needed as it would be assumed that vehicles can move into the oncoming lanes to pass bike riders and thus give enough clearances. This however, leaves bike riders exposed when two vehicles meet while passing a rider that requires one or both vehicles to check their speed to avoid a close passing.

Austroads Guide to Road Design Part 6A details the requirements for a smooth and non-slip surface for bike riders. Surface defects should be less than 10mm and the gravel aggregate size should be less than 10mm. See our page on surfaces for cycling.
 

What do we say about the guidelines?

The road design guides are clear about the width of shoulder required by bike riders and the surface conditions needed by bike riders. They do not provide guidance, however on how to prioritise implementation. Due to the long lengths of rural road and limited budgets not all roads can be provided with rideable shoulders. There is also no specific guidance on measures to improve conditions for bike riders on narrow low volume rural roads. These could include sealing the insides of corners and other measures recommended above.
 

Examples, good and bad

 Examples from other popular on-road fitness routes in Victoria 

Dookie Shepparton Rd, near Shepparton (thanks to google map street view)

A popular fitness route (the 60km east loop) ridden mostly in one direction.

The inside of this corner has been sealed to provide more room for bike riders and a smoother space free of gravel.

Surf Coast Hwy to Torquay, near Mt Duneed (thanks to google map street view)

A shoulder has been provided along most of this divided road. It is a different colour (red) and mostly adequate width (1.5m).

Unfortunately the surface is rough and less comfortable than the road surface itself for bike riders.

It also ends before reaching the destination (Torquay) and at some major intersections.