This part of Glenlyon road has four lanes. Two bicycle lanes and two lanes for vehicles which are not bicycles. The bicycle lane at the location I documented is 1400 millimetres wide. The speed limit is 60 kilometres per hour.

I am referring to the Austroads guide to traffic engineering practice, part 14: Bicycles. Section 4.3.1 of this document discussed "Shared bicycle/parking lanes".

This document specifies a desirable mininum width for a bicycle parking lane of 4.0 metres. This includes one metre of manoevouring space for the bicycle and a further 0.2 metres lateral clearance between the bicycle manoevouring space and an open car door.

Section 4.3.4 Exclusive Bicycle Lanes discusses the delineation of bicycle lanes:

(Bicycle lanes) should preferably not be delineated with raised pavement markers or raised bariers as these are hazardous to cyclists;

The bicycle lane in this part of Glenlyon road is much narrower than is specified by the guide to traffic engineering practice. The guidelines specify 1200mm between the open door of a power vehicle and the line which divides the bicycle lane from the next lane to the right. Because space is limited, bicycles stay as far to the right as possible.

R0019127.JPG shows a power vehicle with an open door on Glenlyon road. I measured 500mm between the open door and the raised barrier.

R0019129.JPG shows a power vehicle partly blocking the bicycle lane in Glenlyon road. Bicycles have to merge out of the bicycle lane to avoid vehicles waiting in this position.

Note that the imprinted dates in 2007 are wrong. They should be in 2010.

For a start: the guide to engineering practice says that . For this reason raised pavement markers and barriers should not be used.

The following scenarios illustrate how raised pavement markers can result in problems for bicycles. It is important to remember that bicycle riding places a great load on the cognitive resources of bicycle riders. It is not always possibly for bike riders to identify and avoid hazards such as raised pavement markers. Adverse lighting and precipitation also create distractions and additional hazards. We should consider what happens when the bicycle rider is unable to locate the raised pavement on the road surface and contacts it unexpectedly.

To expand on this, Raised pavement markers and barriers are a hazard because they interfere with traction, particularly when crossed at a shallow angle and when water is present on the road surface.

Bicycles need to leave bicycle lanes to avoid hazards such as opening doors, vehciles entering from side roads and vehicles leaving parking spaces. When turning the bicycle rider relies on friction between their tyres and the road surface to keep from falling. If the wheel of the bicycle strikes an obstruction a crash may result. Raised pavement markers and barriers are harder to cross because of the steeper angle they present to wheels. They also disrupt the natural drainage of water across the road. Pooling water causes aquaplaning.

The narrow bicycle lane in Glenlyon road encourages bicycle riders to ride close to the pavement markers. If they turn out of the bicycle lane they will do this at a shallow angle. Thick painted lane markings can be a hazard under wet conditions. Tactile edging and raised markers (reflectors) are also a hazard. In a shallow turn there is always a risk that the wheels of the bike will follow a linear obstruction or channel in the road surface, while the body of the bike rider goes in a different direction. The raised barriers used here cause a dangerous linear obstruction.

A bicycle which strikes the end of a raised barrier faces different problems. Asymetric loads on the front wheel could torque the steering to the left or right. The vehicle may straddle the barrier with the front wheel on one side and the back wheel on the other side. This can cause a loss of traction and a crash.

Because the raised barriers represent a hazard to bicycles it is likely that bicycle riders will avoid them by riding further to the right or left of the barriers. Riding further to the left exposes the bicycles to conflict with static hazards such as car doors and pedestrains. Riding to the right of barriers increases conflict with overtaking power vehicles.

Consider a situation where the bicycle is turning to the right and merging across the raised markers. If both wheels hit the raised marker they will have to slide up and across the marker, then down the other side. The wheel may break contact with the marker at the peak in the middle and only contact the road surface beyond the marker. In this case a skid may result, with the application of brakes and resulting brake lockup being a factor as well.

In the case were only one wheel strikes the raised marker the bicycle may experience either under or oversteer. This may result in collision with parked vehicles in the bicycle parking lane.

raised_line_markings.pdf

These surfaces are installed on pedestrian crossings. This is a photograph of one near my house:

R0019130.JPG

A couple of years ago, at the intersection of Princes Park Drive, Cemetary Road West, and College Cresent I nearly crashed on one of these surfaces, while crossing at a pedestrian crossing. There is no alternative at this location to cycle on the pedestrian crossing because it is at the end of a contraflow lane, and the only provision for movements to the north is on the pedestrian crossing.

As I crossed on to the road my back wheel slipped to the left on the plastic surface. It only stopped slipping when the wheel left the plastic surface. These surfaces are used on many shared footpaths and I regard them as a traction hazard for bicycles there too.

Any bicycle riders who want to comment on this trial should send their comments to the City of Moreland via their contact page

1. Start a right turn
2. Overtake another bicycle
3. Pass a car which has its door open
4. Pass a pedestrian who may be walking to their car
5. Pass a car which is starting to turn out of a parking space
6. Pass a car which has stopped to reverse into a parking space
7. Pass a car which is double parked
8. Pass a service vehicle such as a garbage truck
9. Leave the bicycle lane where it ends
10. Leave the bicycle lane before it ends to integrate with the traffic at the end of a queue
11. Avoid debris in the bicycle lane
12. Avoid a broken or dislodged raised line barrier
13. Avoid road works
14. Avoid temporary buildings at construction sites
15. Avoid wide vehicles at construction sites
16. Avoid flooded road surfaces
17. Because lighting conditions make it impossible to see the location of the bicycle lane
18. Pass a car which may be about to open its door or turn into the bicycle lane
19. To avoid a collision, for example where a car has opened its door ahead of the bicycle
20. Merging into the bicycle lane after turning right into the road
21. Merging into the bicycle lane after turning left into the road
22. Avoid pedestrians who are crossing the road
23. Avoid pedestrians who are opening the drivers side door of a car
24. Avoid equipment and materials which are being loaded and offloaded from vehicles
25. To keep a bicycle upright in a strong crosswind

Raised markers have been installed in Gatehouse drive, Parkville.

R0019138.JPG and R0019131.JPG show two different sections of raised marker which are no longer attached to the road surface.

Raised markers which become displaced from their expected location are very dangerous for bicycle riders. Bicycles may find it impossible to avoid the markers when riding a straight line in the bicycle lane. Additionally bicycles may have to leave the bicycle lane to avoid the markers.

The raised markers in Glenlyon road will experience asymetric sheering forces from cars and trucks entering and leaving parking spaces. These forces will eventually damage their mounting points and allow the markers to change position.