Perceived danger acts as a major barrier to the uptake of cycling as a sustainable mode of transport. Therefore, a greater understanding of how these perceptions arise and how they are overcome is necessary.
That's an interesting question that is certainly interesting enough to warrant more research. I found the following study by Elvik and Bjørnskau interesting and helpful: http://www.sciencedirect.com/science/article/pii/S0001457505000825
Regarding considerations in perceived safety, Heinen et al mention several factors in their literature review on cycling such as separation from motorized traffic and bicycle paths: http://www.tandfonline.com/doi/abs/10.1080/01441640903187001#.UgqXqaDCSdI
Some more innovative techniques may be available if you look at the literature on risk compensation, e.g. a paper which relates this to wearing helmets http://www.sciencedirect.com/science/article/pii/S1369847812000587 Some researchers have shifted from risk- Homeostasis to task difficulty Homeostasis, e.g.Fuller’s task-difficulty homeostasis model. You may find inspiration in methods to measure task demands.
I have published a new paper on this area, which uses mental mapping and a Generalised Linear Mixed Model to unpack perceived cycling risk: http://www.sciencedirect.com/science/article/pii/S0001457515301688