Red light enforcement cameras to reduce traffic violations and road traffic injuries: A systematic review

Research Institution / Organisation

London School of Hygiene & Tropical Medicine

Principal Researcher

Dr Phil Edwards

Level of Research

Professional / Work-based

Project Start Date

November 2015

Research Context


Signalised junctions are a fundamental way of regulating traffic, particularly in urban areas. Traffic violations occur when a driver enters an intersection after the traffic light signal has turned to red. These violations can have severe consequences when they result in collisions, causing damage to vehicles and road users. While such traffic crashes may cause damage to property only, they can be serious, particularly when colliding at speed into the sides of other vehicles.


To update and expand a Cochrane systematic review of red light enforcement cameras.

Research Methodology

Search strategy

We will search the following electronic databases:

  • Ovid MEDLINE(R);
  • Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations;
  • Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R);
  • Ovid TRANSPORT (includes the Transport Research Information Services (TRIS), The International Road Research Documentation (IRRD) and The European Conference of Ministers of Transport (TRANSDOC) databases);
  • National Police Library;
  • Embase Classic+Embase (OvidSP);
  • PubMed (current);
  • EBSCO;
  • Web of Knowledge;
  • Heritage.

We will search a broad range of websites for reports and grey literature.


Selection criteria

We will include both experimental and observational studies of red-light cameras. Experimental study designs will be used to provide evidence of effectiveness, and may include controlled-before-after (CBA) studies, controlled interrupted time series, and randomised controlled trials. Observational study designs will be included to provide details of mechanisms, moderators, implementation and economic costs, and may include cohort, cross-sectional, or case-control studies.


Data collection and analysis

Two review authors will independently examine the titles, abstracts, and keywords of electronic records for eligibility according to the inclusion criteria. The full-text reports of potentially eligible studies will be independently assessed for final inclusion in the review by two review authors using screening codes in EPPI-Reviewer 4. Any disagreements will be resolved by discussion with a third review author. Reference lists of all eligible trials will be searched for further eligible studies. Two review authors will independently code relevant data in EPPI Reviewer using a standardised data coding set. The primary outcome will be the number of red-light violations (i.e., number/proportion of vehicles passing through red lights, i.e. not amber). Secondary outcomes will include number of traffic crashes, number of traffic crashes resulting in injury, number of crashes resulting in fatalities or serious injuries, and number of damage only collisions. We will also seek data on economic outcomes (including costs of providing the intervention and income generated by the intervention) and process outcomes (e.g. data on implementation).

Interim reports and publications

‚ÄčNot available

Date due for completion

September 2017
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