Safety Issues

of

Shared-Use Paths

May 2007

Dr. Oksana Holubowycz

Dr. Holubowycz PhD [MPH Epidemiology – UNC, Chapel Hill, USA] previously worked as

an injury epidemiologist at the NHMRC Road Accident Research Unit in Adelaide and

currently is a University of Adelaide Research Fellow in the Discipline of Orthopedics and

Trauma at the Royal Adelaide Hospital, which is the major center for treating injuries in

South Australia.

SAFETY ISSUES OF SHARED-USE PATHS

SUMMARY:

• There is new scientific literature which describes the risks of bicycle into pedestrian collisions on shared bicycle-pedestrian paths

• This has important implications for Council in terms of siting of shared use paths, maintenance and legal liability, which may also increase the costs borne by ratepayers:

- A coastal shared-use path is expensive and difficult to maintain because of the nature of local conditions, especially related to sand being repeatedly blown onto the path, wind and erosion.

- High maintenance standards are required to ensure that safety is not compromised.

- If an injury on a shared-use path is found to have been contributed to by poor condition of the path, then the body responsible for path maintenance, most likely the local Council, will be legally liable.

- Further liability is likely to arise if a shared-use path is built in a location known from the start to be subject to adverse conditions, such as accumulation of sand and other debris, and high winds, all of which increase the risk of collisions, rather than building a path in a more protected area.

• A coastal shared-use path will potentially bring together individuals most at risk of being involved in a collision, either between bicycle and pedestrian/skater or between skater and pedestrian.
• The nature of the pedestrian users of a coastal path, particularly the young and elderly, is likely to increase the severity of injury, given a collision.

SAFETY ISSUES OF SHARED-USE PATHS

Recent reports have highlighted the safety issues on shared-use paths.

Prior to this, understanding of the safety issues of shared-use paths has been limited by lack of data on incidents occurring on shared-use paths and lack of data on use of shared-use paths.

Because of the lack of officially-recorded data on incidents and injuries on shared-use paths, a

survey was recently undertaken by the University of Connecticut for the Connecticut Department of  Transportation (Aultman-Hall & LaMondia, 2005):

• 684 users of shared-use paths were surveyed in the pilot study

• 51 collision or fall events were reported

• 35 of these 51 events resulted in injuries

• two of these injuries were serious

• it is important to note that such samples under-estimate incidents and injuries because the

injured are more likely to have stopped using shared-use paths

• one of the conclusions drawn by the researchers was that consideration be given to separating different user types

Another recently published scientific paper emphasizes that “with the expansion of bicycle usage and shared bicycle-pedestrian paths, there is increased risk of bicycle into pedestrian collisions” (Short et al., 2007). There has been little research on cyclist-pedestrian impacts and factors influencing injury severity in such collisions.

What is known is that:

• above a threshold impact speed of 15 km/hr, the distance that the pedestrian was thrown increased in accordance with the increase in speed (Short et al., 2007)
• the impact of the pedestrian’s head with the pavement because of the subsequent fall, rather than the initial impact between the bicycle and pedestrian, is the cause of the most severe injury to the pedestrian (Short et al., 2007; Graw &König, 2002)
• in on-road accidents, pedestrians involved in pedestrian-bicycle collisions are most commonly elderly
• the elderly are frequently more severely injured even when impact speeds are comparatively low (Graw &König, 2002).

In considering the safety of shared-use paths, it is important to examine three key issues:

(1) who are the potential users of a shared-use path along the coast,

(2) how the characteristics of the users may exacerbate both the frequency and severity of injury

and

(3) how can paths, either shared or separate, be best sited to avoid adverse conditions that

predispose to injury.

Who is most likely to use a coastal shared-use path?

• pedestrians for whom walking on the beach is difficult, namely the elderly and in particular the frail elderly, people with disabilities, those using walking aids and family groups with young children
• in-line skaters or roller skaters
• bicyclists who are often recreational and cycling in small groups and ill-equipped to avoid collisions

On the basis of the above discussion, it is not difficult to see that:

(1) a coastal shared-use path will potentially bring together individuals most at risk of being involved in a collision, either between bicycle and pedestrian/skater or between skater and pedestrian,

(2) the nature of the pedestrian users is likely to increase the severity of injury, given a

collision, and

(3) the potential for collisions will be worse in adverse conditions, such as exposure to wind and sand blown onto the path.

Significant issues which must be considered in any discussion on the safety of coastal shared-use paths include:

(1) Maintenance costs

- high maintenance standards are required to ensure that safety is not compromised, for

example by sand and other debris on paths and erosion around the path shoulders leading

to cracks

- frequency of routine maintenance and how reported maintenance concerns are to be

handled are critical issues

- a coastal shared-use path is expensive and difficult to maintain because of the nature of

local conditions, especially related to sand being repeatedly blown onto the path, wind and

erosion.

(2) Liability

- if an injury on a shared-use path is found to have been contributed to by poor

condition of the path, then the body responsible for path maintenance, most likely the local Council, may be legally liable

- further liability is likely to arise if a shared-use path is built in a location known from the start to be subject to adverse conditions, such as accumulation of sand and other debris, and high winds, all of which increase the risk of collisions, rather than building a path in a more protected area.

Notes:

• agencies which are involved in collating data on injuries only collect data on pedestrian and bicyclist related deaths and injuries that occur on regular roadways
• even on roads, there is significant under-reporting of incidents involving pedestrians and bicyclists: one study found that about 75% of accidents involving pedestrians and bicyclists were not reported (Hautzinger et al., 1993, cited by Graw & König, 2002)
• almost all incidents involving pedestrians or bicyclists on shared-use paths have, until now, been largely unreported

Aultman-Hall L, LaMondia J. Evaluating the safety of shared-use paths. Transportation Researc Record 2005;1939:99-106.

Short A, Grzebieta RH, Arndt N. Estimating bicyclist into pedestrian collision speed. International Journal of Crashworthiness (in press)

Graw M, König HG. Fatal pedestrian-bicycle collisions. Forensic Science International

2002;126:241-247.