Effectiveness of speed cameras in reducing speed: a systematic review.

Speeding has been identified as one of the most common risk factors for the occurrence and severity of traffic accidents. One of the most economical and widespread strategies for speed management is the installation of Speed Cameras (SC). In light of the growing body of evidence in this field and the need for a coherent synthesis of research findings, challenges and gaps, this paper provides a systematic review and an integrated overview of the current state of knowledge on the topic. Five electronic databases (SCOPUS, Web of Science, PubMED, TRID and PROQuest) were used to identify relevant studies. Records were identified, screened, and assessed using a structured multi-stage review process consistent with established systematic review procedures. The included studies reported investigations related to the SC impact on driving speed. A systematic classification scheme was adapted to summarize the study's characteristics. Ninety-four studies were identified. As a result, issues in the study objects, methods and procedures of SC evaluation and impact on vehicle speed assessment were discussed. In particular, due to the complex road environment, other factors also impact driving speed patterns. Additionally, it is demonstrated that the impact of SC on speeds has been assessed by four methods: self-reported questionnaires and location, time, and cross-sectional speed analysis. Complementary research on the following themes would provide interesting insights on SC related studies: understanding how other urban environment factors can influence SC effectiveness; settlement of compliance distance, continuous speed measuring methods associated with time and location speed analysis, and evaluation of the impact of road type, speed limit, and geometry.