According to the bicycle network, a boardwalk on the Yarra Trail in Melbourne, Australia has had an ongoing history of bicycle crashes due to its slick and uneven wooden surface and poor fence line. In Melbourne, there was a bike rider who fell from a boardwalk in 2010 and died.
When looking into boardwalks and bridges you should look for the following risks:
In order to solve these issues, the path should be designed or fixed in order to reduce as many risks as possible. If a boardwalk needs to be narrow and curved, then slopes should be avoided, sight lines should be clear and fences should be high. Also, a smooth non-slip surface should be provided. If a path is sloped and curved, then it should be slip resistant and kept wide with clear sight lines.
There are many pros and cons to different boardwalk surfaces such as concrete, wooden boards, slated wood or metal. Concrete is durable and integrates sand cement which provides slip resistance, although it needs a substructure for support and it tends to be more expensive. Wooden surfaces tend to be slippery when wet, usually require an additional non-slip surface and the boards may lift up after time. This type of surface is mainly used for walking rather than riding. Metal offers durability, longevity and a slip resistant surface if coated properly, although it may be a bit more expensive.
“Boardwalks & Bridges”. Bicycle Network Victoria: Good Design Guides. http://www.bv.com.au/general/bike-futures/42436/