Below is the summary of a longer report that deals with possible approaches to a “Share the Road” innitiative. The full report is on the following link – it is over 30 pages Cycling in traffic
There are health, congestion, environmental and economic benefits when replacing car trips with bicycle trips. To get those benefits more people have to ride to work, schools, train stations or shops instead of using their cars. Many people who are healthy, have access to a bicycle and live within cycling distance of their destination choose to use their cars because they are afraid of using a bicycle in traffic. The cycling academic John Pucher talks about riding a bicycle as “a benign activity carried out in a dangerous environment”, with the benefits of cycling outweighing the risks.
The cyclists we see mixing with traffic are the experienced commuters and the experienced recreational riders in groups. They are the least vulnerable of all the people of bicycles, and will ride irrespective of external circumstances such as weather or traffic, but only account for 1% to 4% of the population. Most of the 22% of West Australians that rode a bicycle last week did so for recreation, and many of them are fearful of sharing roads with motorised traffic. This large segment, already used to cycling, would use a bicycle to go the shops, school, train stations or places of employment if they feel it is safe.
Amongst the general car driving public there is a perception that cyclists are using roads irresponsibly, with the “running” of red lights the main annoyance. But only a small proportion of people on bicycles behave in an inconsiderate fashion. For instance in Melbourne (the cycling capital of Australia) six times more pedestrians ignore red lights than cyclists, without attracting any bad publicity. In European cities people on bicycles are generally more responsible and compliant traffic participants, demonstrating that in places where cycling is part of mainstream traffic, cyclists are more likely to obey traffic rules.
Drivers see the key function of streets as providing transport and belonging to motorised traffic that can easily accelerate to 50 kph plus and go up grades without slowing, and consider the cyclists presence on the road as annoying. This annoyance can lead to dangerously close passing, creating circumstances were crashes may more easily happen. Prominent reasons why people do not ride a bicycle for transport are: unsafe road conditions, the speed and volume of traffic, and the lack of segregated infrastructure. The biggest fear of on-road cycling commuters is to be run over by a car travelling in the same direction. Although only a small proportion of injured cyclists admitted to hospitals were involved in a collision with a motor vehicle, they are normally the more severely injured, and about 90% of cyclist deaths involve a motor vehicle. A legalised safe passing distance would make close overtaking less likely.
Opponents of a legalised passing distance incorrectly cite a study from Baltimore that examines the effects of a 3-foot legalised passing distance (Love et al., 2012), saying that it is not effective. But the data in the study strongly suggests that a legalised passing distance works: in the study there was not a single case where a car overtook a cyclist with less than 2’6” clearance.
To mitigate the fear that people on bicycles have when they are riding in traffic, “share the road” campaigns target road user behaviour, often trying to improve both motorist and cyclist behaviour. There are many examples of behaviour change campaigns that seek to benefit vulnerable road users in Australia and overseas. Some of the slogans are: “Cool it, Bell it, Slow it, Share it”, “We can all share the road safely, please give us a chance”, “We just have to learn to get along”, “We all share the road, so respect cyclists” etc, etc.
A campaign that benefits people on bicycles has to confront the issue of cars and car drivers. It has to aim to change the mindset of car drivers so that they can accept that lower speed in suburbs, a legalised safe passing distance and money spent on separate infrastructure for people on bicycles are desirable, necessary and ultimately in their favour.
A legalised safe passing distance would be more useful if it were supported by a law that ensures a safe environment for all vulnerable road users. The Vulnerable User Law can be explained quite simply in the legislation—the person operating the heaviest vehicle is responsible to operate their vehicle in such a manner that they are ensuring the safety of the more vulnerable users with whom they are sharing the road. Simply, if motorist hits a cyclist, the motorist is at fault; if a cyclist hits a pedestrian, the cyclist is at fault. 
The strongest approach for West Australia would be the legislation of a safe passing distance, followed by a campaign that shows motorists how vulnerable people of bicycles are, explains the need for a generous passing distance, and makes motorists aware of the benefits cyclists bring to the community in terms of environment and congestion.
 As suggested in a report by Alan Voorhees for the Department of Transportation of New Jersey (USA)