Scientific evidence on road safety effects of section control and red light cameras Dublin, ITS Ireland, 17 September 2013 Charles Goldenbeld, Institute for Road Safety Research SWOV

This presentation Institute for Road Safety Research SWOV Scientific evidence section control Separate studies Soole et al. review 2013 Dutch experience Acceptance Conclusions Scientific evidence red light cameras International reviews (Cochrane 2005, Erke 2009, Høye 2013) Dutch experience Acceptance Conclusions Dublin, ITS Ireland, 17 September 2013

What SWOV stands for Mission: to improve road safety with knowledge from scientific research Public knowledge for professionals Network organization, top institute national and international Dublin, ITS Ireland, 17 September 2013

What we do In-depth studies into the causes of accidents Experimental research Evaluation studies Data analysis Calculating the effects of policy plans Second opinions Independent, multidisciplinary, high quality Dublin, ITS Ireland, 17 September 2013

Who we work for Road safety professionals: –National, regional and local authorities –Police and judicial authorities –Consultants –Trade and industry Dublin, ITS Ireland, 17 September 2013

Section control: Terminology Section speed control Average speed control Point-to-point speed control Dublin, ITS Ireland, 17 September 2013

Section control Dublin, ITS Ireland, 17 September 2013 Figure from: Soole, Watson, & Fleiter, J.F. (2013). Effects of average speed enforcement on speed compliance and crashes: A review of the literature. Accident Analysis and Prevention, 45,

Scientific evidence section control CountryReference Austria Stefan, C. (2006) Section control – automatic speed enforcement in the Kaisermühlen tunnel (Vienna, A22 Motorway). Austrian Road Safety Board (KvF), Vienna Australia Lynch, M., White, M. & Napier, R. (2011). Investigation into the use of point-to-point speed cameras December NZ Transport Agency research report 465, Wellington, New Zealand. Italy Montella, A., Persaud, B., D'Apuzzo, M., & Imbriani, L. (2012). Safety evaluation of automated section speed enforcement system. Transportation Research Record, (2281), pp International review Soole, D.W., Watson, B.C., & Fleiter, J.F. (2013). Effects of average speed enforcement on speed compliance and crashes: A review of the literature. Accident Analysis and Prevention, 45, Netherlands Rijkswaterstaat Directie Zuid-Holland, Afdeling VIV (2003). Evaluatie 80 km/uur maatregel A13 Overschie. Doorstroming en verkeersveiligheid. Rijkswaterstaat, Den Haag. Norway Ragnøy, A. (2011).Automatic section speed control. Results of Evaluation. Norwegian Public Roads Administration, Directorate of Public Roads, Oslo. Dublin, ITS Ireland, 17 September 2013

Section control separate studies SourceStudy characteristicsResults Stefan 2006 Kaisermühlen tunnel Vienna motorway Road type: 2- tube tunnel, 3-4 lanes per direction Tunnel section length: 2,3 km Speed limit: 80 km/hr. cars; 60 km/hr HGV Before period 4 yrs.; after period 2 yrs. Speed reduction: - Daytime cars: 85  75 - Daytime HGV 70  55 - Nighttime cars: 95  75 - Nighttime HGV: 75  55 Reduction air pollutants: - CO: -15% - NO x -39% Crash reduction: - Injury crashes: -33% - Fatal and serious crashes: -49% Cost Benefit Ratio estimate 5,3 Montella et al Italian Motorway Al Milan-Naples Road type: Divided highway, 3 lanes Section length: 80 km Speed limit: 130km/hr. Before period 6,5 yrs.; after period 2,5 yrs. Motorway Napels-Candele A16 used as reference group (255 km length) Crash reduction: - Total crashes -31% - Severe crashes -55% Crash reduction decreased over time

Separate studies SourceStudy characteristicsResults Ragnøy, sections Road type: two 2-lane, one 2/3-lane (rural highways) Section length 8.6, 5, 9.5 km Speed limit: 80 km/hr. Study mainly concerned with measuring vehicle speeds Average speed reduction (km/h): - 2.7; -8.8; Estimated speed reduction one location: - Spot speed control -3.3km/h - Section speed control -8.3 km/h Estimated total crash reduction: - Spot speed control -10% - Section speed control -23% Estimated fatality reduction - Spot speed control -16% - Section speed control -35% Dublin, ITS Ireland, 17 September 2013

Section control: Effects speeds/crashes/cost- benefit estimates. Soole et al review SWOVDublin, 17 September 2013 Uitvoering OutcomesCountryResults Effects on vehicle speeds Austria, Australia, Italy, France, Netherlands, UK Offences rates < 1%, more homogenised speeds Crash/injury reduction Austria, Italy, Netherlands, UK Reduction effect on fatalities and serious injury crashes (40% - 65%). However: weak methods

Section control: comparative performance & cost benefit. Soole et al review Dublin, ITS Ireland, 17 September 2013 Outcomes CountryResults Relative performance compared to spot speed enforcement England, UK -Offences rates 11 times lower at road works than with traditional speed enforcement -Gains et al study: particularly effective in reducing extreme speeding (i.e. 15 mph over limit) -Nottingham study: crash reduction with average speed control at three sites versus crash increase at three fixed camera sites Cost-benefit CB Austria, Australia, UK Austria: CB-ratio 5,3 (actual findings) England, A14: annual overall CB £ 4.3 million UK based on modelling fuel consumption/vehicle emissons: 70 mph UK motorway: CB-ratio mph UK motorway: CB-ratio 7.1 (excluding costs reduction crashes/congestion!) Australian estimates: CB-ratios , 10

Dutch Experience: Section control in the Netherlands Pilot testing 1997 Introduced 2002 Financed by funds enabled by the Dutch ‘Climate Bill’ (1998) Systems distinguishes motorcycles, cars, buses, trucks, lorries Fines starting from 7 km/hr. above limit (80, 100, 120, 130) In 2013: 13 section control systems in operation in the Netherlands 3 section control systems include several sections (only one fine is given!) A 2002 evaluation of section control (including limit change 100 km/hr.  80km/hr.) on motorway near Rotterdam ( vehicle per day 10% heavy trucks) showed positive effects: –Speed: < 1% offenders of 80 km/hr. limit –Crashes: 47% reduction all crashes, 46% reduction persons injured –Climate: Absolute NO 2 -concentrations lowered by 4% to 6% –Noise: Reduction of daily noise levels by 0,4 dB In general: 99,5% drivers comply with speed regime under section control Dublin, ITS Ireland, 17 September 2013

Section control acceptance Country, reference Survey Results (mentioned in Soole et al. except *) France, Schwab % French driver report to reduce speed in answer to advisory sectio con5trol system enforcement not included!) Netherlands, Poppeliers et al. 2009* 77% Dutch drivers consider section control (very) acceptable UK, Charlesworth % UK motorists report compliance with section control UK, Crawford % British drivers welcome section control on residential roads New South Wales, Australia, Walker et al % support the use of section control Norway, Sweden, Denmark Bjørnskau et al. 2010* A majority in all three countries is in favour of introduction of section control

Conclusions Section control Dublin, ITS Ireland, 17 September 2013 Preliminary findings are very encouraging (positive & large effects: average speeds, extreme speeds, homogenised speeds, crashes, vehicle emissions, reliability journey time, public acceptance, favourable cost-benefit estimates) Broad applicability - Motorways - UK also on: Urban arterials - Road works - Tunnels - Mobile systems Word of Caution: 1. although the available evidence is consistently positive, much of the evidence is lacking in strict scientific rigour (e.g. presence adequate control group, adjustment regression to the mean) 2. section control is complementary to other speed management measures, not a replacement for road design or maintenance deficiencies

Dublin, ITS Ireland, 17 September 2013 Red light cameras = RLCs Evidence typeAdvantageDisadvantage Separate research studies It can be wise to look and learn from one well-controlled study Results of separate studies often too particular, not generalisible Qualitative Review Literature review Identification of variables that moderate effects No precise overall estimate, no ‘statistical’ precision/ proof Quantitative review (e.g. Cochrane) Qantitative estimate overall effects Often few studies that meet quality criteria Meta-analysisQuantitative estimate overall effect, estimate of moderator effect Sources of bias, e.g. publication bias; comparing apples and oranges

Scientific evidence: major quantitative review studies RLCs Evidence Type Reference International quantitative review Aeron-Thomas, A. S. & Hess, S. (2005). Red-Light Cameras for the Prevention of Road Traffic Crashes. Cochrane Database of Systematic Reviews 2005, Issue 2, Art. no. CD Oxfordshire, England: The Chochrane Collaboration. Meta-analysis Erke, A. (2009). Red light for red-light cameras? A meta-analysis of the effects of red-light cameras on crashes. In: Accident Analysis & Prevention, 41, nr. 5, p Criticism on meta-analysis Lund, A.K., Kyrychenko, S.Y. & Retting, R.A. (2009). Caution: A comment on Alena Erke’s Red light for red-light cameras? A meta- analysis of the effects of red-light cameras on crashes. doi: /j.aap In: Accident Analysis & Prevention, vol. 41, nr. 4, p. 895–896. Meta-analysis Høye, A. (2013). Still red light for red light cameras? An update. Accident Analysis and Prevention, 55, p Dublin, ITS Ireland, 17 September 2013

Aeron-Thomas & Hess 2005, (Cochrane review) Two reviewers independently extracted data on study type, characteristics of camera and control areas, and data collection period 10 controlled before-after studies from Australia, Singapore and the USA met inclusion criteria concerning method quality Conclusion 1: RLCs are effective in reducing total casualty crashes (based 4/5 studies; only 1 very good). Conclusion 2: The evidence is not conclusive as to whether RLCs reduce right-angle or rear-end casualty crashes or total crashes (including property damage only crashes) and traffic violations. Dublin, ITS Ireland, 17 September 2013

Meta-analysis Erke (2009) Meta-analysis = statistical method of combining effect results of several studies to assess overall effect and influence of moderating variables 21 studies (10 USA, 4 Australia, 3 Singapore, 3 UK, 1 Norway) 5 well-controlled studies Dublin, ITS Ireland, 17 September 2013

Meta-analyses Erke (2009): Taking into account study quality Dublin, ITS Ireland, 17 September 2013 Study aspect Control for… Explanation Regression to the mean RTM Extreme values in a distribution, such as a particularly high number of crashes in an area during one time period, will tend to move toward the average of the entire group of such areas in the succeeding time period, even if nothing is done to affect the crashes. No control RTM  overestimation safety effect Spillover-effectThe installation of RLCs and concurrent publicity may affect red-light running and crashes not only at those intersections at which RLCs are installed but also at nearby intersections without RLCs. Drivers may for example become generally more inclined to stop when lights are changing to red. No control spillover  underestimation safety effect

Main results Erke 2009 (  blue boxes ) Crash typeControl for regression to the mean Control for spill-over effects Best estimate (95% confience interval) All crashesNo -16 (-27: -4) Yes +15 (-3;+38) NS Injury crashesNo -17 (-37; +8) Yes +13 (-10; +43) NS Rear-end-collisionsNo +17 (+6; +31) Yes +43 (+20; +70) Right-angle collisions No -14 (-27: +1) Yes -10 (-31; +19) NS Dublin, ITS Ireland, 17 September 2013

Lund et al criticism Erke 2009 meta-analysis SWOVDublin, ITS Ireland, 17 September 2013 Basic criticism: Erke did not look critically enough to the method quality of studies she has included in her meta-analysis Two of the five studies listed as controlling for regression to the mean and spillover did not in fact control for these factors Three ‘well-controlled’ studies included in meta- analysis were non-peer reviewed and received considerable statistical weights Among the five studies Erke labels “strong,” the two weaker studies received more statistical weight than the three stronger studies. Doel Uitvoering

Recent study Høye 2013: new meta- analysis & answer to earlier criticism The aim of this study was to replicate the results from the study by Erke (2009) based on a larger sample of RLC-studies, and to investigate more thoroughly the effects of study methodology. A closer look is especially taken at those studies that have been critized by Lund et al. (2009) and several analyses are performed to test if these or other studies can be regarded as outliers. Dublin, ITS Ireland, 17 September 2013

Meta-analysis Høye 2013 Dublin, ITS Ireland, 17 September studies included in Erke 2009 plus 9 more recent studies Most studies USA (17), Australie (7), UK (3), Norway (1), Canada (1), Singapore (1) Control for regression-to-the mean NoYes Control for spillover-effects No 8 5 Yes 7 9

Høye 3 step approach meta-analysis Initial meta-regression = to study effects regression- to-the-mean (RTM) and spillover effects Overall effects meta-analysis: effect estimates for studies with and without control RTM Exploratory analyses to explain remaining heterogeneity results –Moderator variables (.e.g. warning signs at all intersections vs. general warning entrance cities) –Publication bias, outlier bias, bias by statistical weighting Dublin, ITS Ireland, 17 September 2013

SWOVDublin, ITS Ireland, 17 September 2013 Doel Uitvoering Crash type Control for regression-to- the mean Change number crashes (%) Best estimate95% CI All crashes, fatal Yes-17(-30; 0) No-63(-83; -23) All crashes, injury Yes-12(-27; +5) No-21(-31; -11) All crashes, unspecified Yes+6(-4; +17) No-17(-24; -9) All crashes, property damage only Yes+3(-31; +53) No-11(-28; +10) Right-angle collisions, injury Yes-33(-48; -12) No-46(-53; -37) Right-angle collisions, unspecified Yes-13(-27; +3) No-29(-40; -15) Rear-end collisions, injury Yes+19(+3; +39) No+18(-7; +51) Rear-end collisions, unspecified Yes+39(+20; +60) No+8(+0; +17) Table 3: Results from meta-analysis of the effects of RLC on numbers of intersection crashes, summary effects and confidence intervals from before-after studies with and without control for regression-to-the mean. Høye 2013 Main results (  blue boxes)

Høye 2013 Further results Dublin, ITS Ireland, 17 September 2013 General warning signs tend to be more effective than separate signs at each intersection (however: not all results in support! ) Some evidence for publication bias, but direction of the results not changed by it In answer to Lund et al criticism: no evidence that meta- analysis results were excessively influenced by outliers or by statistical weighting

Dutch experience: Red light cameras in the Netherlands Estimate: > 600 speed/red light cameras In 2013 fine for red light running: € 220 Few thorough evaluations 2005 study Amersfoort: Positive crash reduction found (15 red light camera intersections compared with 30 control intersections) 2011 national road users survey: –2% drivers report to have been fined for red light running; –71% in favour of installing more red light cameras Dublin, ITS Ireland, 17 September 2013

Acceptance red light cameras Dublin, ITS Ireland, 17 September 2013 Dutch survey 2011: 71% in favour of more red light cameras European drivers survey 2010: 72% support (SARTRE-4) Insurance Institute for Highway Safety Status Report April 2013: 87% support RLC among those who live in areas with long-standing automated enforcement Acceptance even higher when pedestrian, cyclist viewpoints taken into account

Conclusions red light cameras Dublin, ITS Ireland, 17 September 2013 Høye 2013 meta-analysis: Evidence for road safety effects red light cameras is positive but still less strong than we would like it to be  Best estimate, best studies: -12% injury crashes (not significant)  Best estimate, best studies: -33% right-angle injury collisions (significant)  Best estimate, best studies: +19% rear-end injury collisions (significant) Complexity of intersections: Large inter- and intra-study variation: variables that may be of importance are: the phasing of the traffic lights, the offence rate before the cameras were placed, early warning signs about the cameras, and the cameras' visibility. Red light cameras are only one candidate measure for problems with red light running; start with proper, complete problem-analysis Red light cameras are likely not the best solution when crashes are related to congestion, inattentive driving, or long signal delays

Thanks for you attention! Dublin, ITS Ireland, 17 September 2013