Table 5.

Description of included systematic reviews: Structural improvement

Review first author, date of publication	Date of search to identify studies for this review	Interventions	Participants	Number of included studies (types of studies)	Geographic area	Studied Outcomes
Beyer 2009 [47]	October 2008	Street lights	Streets or groups of streets	17 (controlled before and after studies)	HIC (USA, UK, Australia, Germany)	. Slight reduction in crashes . Slight reduction in fatal and injury crashes
Elvik 2003 [48]	1997	Roundabouts	Intersections	28 (before and after, comparative study)	HIC (Britain, Sweden, Denmark, Norway, Australia, Netherlands, Switzerland)	. Reduction in number of injury and fatal crashes
Elvik 2017 [49]	Not stated	Roundabouts	Junctions	44 (before and after, comparative study, cross-sectional studies)	HIC (Britain, Sweden, Denmark, Norway, Australia, Netherlands, Switzerland, USA, Belgium)	. Reduction in number of crashes
Fu 2016 [50]	February 2015	Digital countdown timers	Motorists	14 (cross-sectional studies, before and after studies)	HIC (Taiwan, China, Singapore, Slovenia) MIC (Thailand) LMIC (India)	. No reduction in rear-end collision . No effectiveness in DCT on intersections.