The OECD (1986) recommended that intervention projects should be evaluated, and this is a wise counsel. However, evaluation must be carried out well, with a view to the way the results can be used. Wagenaar et al. (1995) pointed out that when evaluations are designed weakly they are hard to interpret, and if they do not report suitable statistics it is difficult to use their data in meta-analysis, a very powerful way of drawing conclusions across several studies. Results of meta-analyses have been reported in the relevant sections above.
One difficulty with evaluating accident prevention is the rarity of accidents. Meta- analysis can help overcome this problem, but investigators have also explored the use of proxy measures. For example, Silcock et al. (1998) used ‘‘encounters’’ between pedestrians and vehicles as a proxy. Such proxies may also be useful in evaluations (Davis et al., 1989).
PROMISING (2001) noted that the effectiveness of a given intervention could vary between countries. They gave the example of cycleways (p. 63), which have been found to change the number of bicycle accidents between17% (Denmark) to +73% (USA). As with any empirical research, care must be taken in generalising findings to dissimilar contexts. Differences such as level of pedestrian activity, traffic patterns and road layout will affect the possibility of generalising.
Typically, innovators carry out their own evaluations. We particularly recommend that the evaluation of interventions should be carried out independently of those designing interventions.
7.6
Summary
Interventions can be targeted at older pedestrians themselves, other road users, and the road environment. Because older people are so vulnerable to the consequences of physical injury, there is an onus on the system designer to minimise potential conflicts between older pedestrians and vehicles through the design of the road environment. However, interventions must be evaluated systematically and objectively to develop effective solutions, and to help achieve a balance between costs and benefits.
7.6.1 Information and training aimed at older pedestrians or other road
users
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Few existing programmes to develop information for broad distribution to older pedestrians were found. Evaluations suggest that even if such programmes affect knowledge, they may not affect practical behaviour.•
A targeted programme, recently trialed in the USA, to encourage better self- regulation by high risk, visually impaired, older drivers has been shown to affect self-reports of relevant behaviour, but validation is incomplete.•
Practical training interventions have been designed to address aspects of performance relevant to the pedestrian task, and these have been shown to achieve their immediate goals. However, there is little direct evidence linking them to changes in behaviour in the road environment or reduced accident risk.•
Information on functional impairment, self-awareness and compensation, and high-risk scenarios can be used to identify advice that should be useful to older pedestrians. However, there is typically not yet direct evidence for a link with reduced accident risk.•
Other road users, particularly drivers, can be effectively targeted by coordinated programmes, and this has been demonstrated to reduce accident risk forpedestrians.
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Psychological research has implications for the effective design of information or training interventions. One specific issue that programmes may need to address to achieve behaviour change is some older people’s weaker belief that accidents are preventable.•
There are technological innovations, such as protective clothing, that might help to reduce accident risk or moderate injuries for older people.7.6.2 Road environment
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Passive interventions, such as signal-controlled crossings and area-wide speed reduction changing the road environment, are likely to be most effective for older pedestrians.•
Standard setting by central authorities, not necessarily central government, is potentially the most effective passive intervention. Guidelines have already been prepared in some countries.•
Modifications to the road environment have been shown to reduce accident and fatality risk. Interventions that reduce vehicle speed, reduce opportunities for conflict between vehicles and pedestrians, and afford protection when apedestrian negotiates the roadway, are effective. Improving the visibility of both pedestrians and vehicles is also effective.