Patrick Morency

Risk of injury for bicycling on cycle tracks versus in the street

Most individuals prefer bicycling separated from motor traffic. However, cycle tracks (physically separated bicycle-exclusive paths along roads, as found in The Netherlands) are discouraged in the USA by engineering guidance that suggests that facilities such as cycle tracks are more dangerous than the street. The objective of this study conducted in Montreal (with a longstanding network of cycle tracks) was to compare bicyclist injury rates on cycle tracks versus in the street. For six cycle tracks and comparable reference streets, vehicle/bicycle crashes and health record injury counts were obtained and use counts conducted. The relative risk (RR) of injury on cycle tracks, compared with reference streets, was determined. Overall, 2.5 times as many cyclists rode on cycle tracks compared with reference streets and there were 8.5 injuries and 10.5 crashes per million bicycle-kilometres. The RR of injury on cycle tracks was 0.72 (95% CI 0.60 to 0.85) compared with bicycling in reference streets. These data suggest that the injury risk of bicycling on cycle tracks is less than bicycling in streets. The construction of cycle tracks should not be discouraged.

The link between built environment, pedestrian activity and pedestrian–vehicle collision occurrence at signalized intersections

This paper studies the influence of built environment (BE) - including land use types, road network connectivity, transit supply and demographic characteristics - on pedestrian activity and pedestrian-vehicle collision occurrence. For this purpose, a two-equation modeling framework is proposed to investigate the effect of built environment on both pedestrian activity and vehicle-pedestrian collision frequency at signalized intersections. Using accident data of ambulance services in the City of Montreal, the applicability of our framework is illustrated. Different model settings were attempted as part of a model sensitivity analysis. Among other results, it was found that the BE in the proximity of an intersection has a powerful association with pedestrian activity but a small direct effect on pedestrian-vehicle collision frequency. This suggests that the impact of BE is mainly mediated through pedestrian activity. In other words, strategies that encourage densification, mix of land uses and increase in transit supply will increase pedestrian activity and may indirectly, with no supplementary safety strategies, increase the total number of injured pedestrians. In accordance with previous research, the number of motor vehicles entering a particular intersection is the main determinant of collision frequency. Our results show that a 30% reduction in the traffic volume would reduce the total number of injured pedestrians by 35% and the average risk of pedestrian collision by 50% at the intersections under analysis. Major arterials are found to have a double negative effect on pedestrian safety. They are positively linked to traffic but negatively associated with pedestrian activity. The proposed framework is useful for the identification of effective pedestrian safety actions, the prediction of pedestrian volumes and the appropriate safety design of new urban developments that encourage walking.

Use of a new public bicycle share program in Montreal, Canada.

BACKGROUND Cycling contributes to physical activity and health. Public bicycle share programs (PBSPs) increase population access to bicycles by deploying bicycles at docking stations throughout a city. Minimal research has systematically examined the prevalence and correlates of PBSP use. PURPOSE To determine the prevalence and correlates of use of a new public bicycle share program called BIXI (name merges the word BIcycle and taXI) implemented in May 2009 in Montreal, Canada. METHODS A total of 2502 adults were recruited to a telephone survey in autumn 2009 via random-digit dialing according to a stratified random sampling design. The prevalence of BIXI bicycle use was estimated. Multivariate logistic regression allowed for identification of correlates of use. Data analysis was conducted in spring and summer 2010. RESULTS The unweighted mean age of respondents was 47.4 (SD=16.8) years and 61.4% were female. The weighted prevalence for use of BIXI bicycles at least once was 8.2%. Significant correlates of BIXI bicycle use were having a BIXI docking station within 250 m of home, being aged 18-24 years, being university educated, being on work leave, and using cycling as the primary mode of transportation to work. CONCLUSIONS A newly implemented public bicycle share program attracts a substantial fraction of the population and is more likely to attract younger and more educated people who currently use cycling as a primary transportation mode.

Aetiology of urethral discharge in Bangui, Central African Republic

Objectives: To determine the aetiology of urethritis in Bangui, Central African Republic. Methods: 410 men presenting with urethral discharge and 100 asymptomatic controls were enrolled. Urethral swabs were obtained and processed by gonococcal culture and polymerase chain reaction for the detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Trichomonas vaginalis, and Ureaplasma urealyticum. Results: In multivariate analyses, M genitalium and C trachomatis were significantly associated with urethral discharge when comparing cases of non-gonococcal urethritis (NGU) with controls. T vaginalis was also more common in cases than in controls, but this reached statistical significance only among cases in whom N gonorrhoeae was also detected. U urealyticum was not associated with urethritis. The gonococcus was found in 69% of cases of urethral discharge. M genitalium was the predominant pathogen in patients with NGU, being found in 42% (53/127) of such patients while C trachomatis was found in only 17% (22/127). T vaginalis was found in 18% (23/127) of patients with NGU, but also in 15% (43/283) of patients with gonococcal urethritis, and two thirds of patients with T vaginalis also had the gonococcus. Multiple infections were common. M genitalium caused a syndrome similar to chlamydial urethritis, with a less severe inflammation than in gonococcal infection. No behavioural or clinical characteristic could discriminate between the various aetiological agents. Conclusions:M genitalium is more prevalent than C trachomatis and is the most common cause of NGU in Bangui. It causes a syndrome similar to chlamydial urethritis. T vaginalis is weakly associated with urethritis, and is often found along with other pathogens.

Risk factors for mortality among children hospitalized because of acute respiratory infections in Bangui, Central African Republic.

Background. Acute respiratory infections are the most common cause of death in children in developing countries. Little information is available on risk factors for mortality among African children presenting with symptoms compatible with acute respiratory infections. Objective. To identify risk factors for death among children hospitalized for respiratory complaints who satisfy the WHO clinical definition for pneumonia or severe pneumonia. Methods. Children <5 years of age who presented with cough and/or difficult breathing and were hospitalized in Bangui during a 1-year period were investigated for risk factors for mortality. The study population consisted of 395 children who satisfied the WHO clinical definition for pneumonia/severe pneumonia. The associations between death and demographic, nutritional, socioeconomic, laboratory and clinical variables were examined. Results. Of the 49 (12.4%) children who died, all but one had had indrawing of the chest which, in univariate analysis, was the risk factor most strongly associated with death [odds ratio, 22.99; 95% confidence interval (CI), 3.81 to 935.2]. In a multivariate model the independent risk factors for death were indrawing of the chest [adjusted odds ratio (AOR) 8.35, CI 1.04 to 66.82], hepatomegaly (AOR 6.72, CI 2.35 to 19.21), age between 2 and 11 months (AOR 6.37, CI 2.18 to 18.59), grunting (AOR 4.53, CI 1.96 to 10.45), a moderate/severe alteration of general status (AOR 3.23, CI 1.17 to 8.94) and acute malnutrition (AOR 2.74, CI 0.96 to 7.78). Conclusions. These findings could be used in flow charts for the management of children with respiratory complaints to identify children at increased risk of death who need to receive aggressive therapy.

From targeted “black spots” to area-wide pedestrian safety

Objective: To describe and illustrate the geographic distribution of pedestrian crash sites in an urban setting (Montreal, Canada) with an alternative data source. Methods: Data on pedestrian victims were extracted for a 5-year period (1999–2003) from ambulance services information systems. The locations of crash sites and pedestrian victim density were mapped using a geographic information system. Pedestrian “black spots” were defined as sites where there had been at least eight pedestrian victims. Results: The 22 identified black spots represent only 1% of all city intersections with at least one victim and 4% of all injured pedestrians, whereas 5082 victims were injured at >3500 different crash sites. The number and population rates of injured pedestrians are greater in central boroughs. Accordingly, the density of pedestrian victims is much higher in central boroughs. Over the 5-year period, in some central boroughs, pedestrian crashes occurred in up to 26% of intersections. Conclusions: Ambulance information systems were relevant to map pedestrian crash sites. Most pedestrians were injured at locations that would have been missed by the black spot approach. This high-risk preventive strategy cannot substantially reduce the total number of injured or the insecurity that many pedestrians experience when walking. Considering the large number and widespread occurrence of pedestrian crashes in Montreal, prevention strategies should include comprehensive environmental measures such as global reduction of traffic volume and speed.

Impact Evaluation of a Public Bicycle Share Program on Cycling: A Case Example of BIXI in Montreal, Quebec

OBJECTIVES We examined associations between residential exposure to BIXI (BIcycle-taXI)-a public bicycle share program implemented in Montreal, Quebec, in 2009, which increases accessibility to cycling by making available 5050 bicycles at 405 bicycle docking stations-and likelihood of cycling (BIXI and non-BIXI) in Montreal over the first 2 years of implementation. METHODS Three population-based samples of adults participated in telephone surveys. Data collection occurred at the launch of the program (spring 2009), and at the end of the first (fall 2009) and second (fall 2010) seasons of implementation. Difference in differences models assessed whether greater cycling was observed for those exposed to BIXI compared with those not exposed at each time point. RESULTS We observed a greater likelihood of cycling for those exposed to the public bicycle share program after the second season of implementation (odds ratio = 2.86; 95% confidence interval = 1.85, 4.42) after we controlled for weather, built environment, and individual variables. CONCLUSIONS The implementation of a public bicycle share program can lead to greater likelihood of cycling among persons living in areas where bicycles are made available.

Understanding the determinants of active transportation to school among children: Evidence of environmental injustice from the Quebec longitudinal study of child development

PURPOSE To examine the combined influence of poverty and dangerousness of the neighborhood on active transportation (AT) to school among a cohort of children followed throughout the early school years. METHODS Growth curve modeling was used to identify determinants of AT to school among 710 children participating in the Quebec Longitudinal Study of Child Development from 2003 through 2006. Parent-reported dangerousness and pedestrian-vehicle collision data were merged with travel mode and health data. RESULTS At age 6 years, insufficient household income, having an older sibling, and living in a neighborhood that is not excellent for raising children, or characterized with high decay were predictive of greater likelihood of using AT and remained unchanged as children progressed from kindergarten through grade 2. CONCLUSION A public health concern is children experiencing environmental injustice. Since AT is most likely to be adopted by those living in poverty and because it is also associated with unsafe environments, some children are experiencing environmental injustice in relation to AT. Interventions may be implemented to reduce environmental injustice through improvements in road safety.

Bicycle Guidelines and Crash Rates on Cycle Tracks in the United States

OBJECTIVES We studied state-adopted bicycle guidelines to determine whether cycle tracks (physically separated, bicycle-exclusive paths adjacent to sidewalks) were recommended, whether they were built, and their crash rate. METHODS We analyzed and compared US bicycle facility guidelines published between 1972 and 1999. We identified 19 cycle tracks in the United States and collected extensive data on cycle track design, usage, and crash history from local communities. We used bicycle counts and crash data to estimate crash rates. RESULTS A bicycle facility guideline written in 1972 endorsed cycle tracks but American Association of State Highway and Transportation Officials (AASHTO) guidelines (1974-1999) discouraged or did not include cycle tracks and did not cite research about crash rates on cycle tracks. For the 19 US cycle tracks we examined, the overall crash rate was 2.3 (95% confidence interval = 1.7, 3.0) per 1 million bicycle kilometers. CONCLUSIONS AASHTO bicycle guidelines are not explicitly based on rigorous or up-to-date research. Our results show that the risk of bicycle-vehicle crashes is lower on US cycle tracks than published crashes rates on roadways. This study and previous investigations support building cycle tracks.

Disaggregate Exposure Measures and Injury Frequency Models of Cyclist Safety at Signalized Intersections

This paper proposes a new approach to represent cyclist risk exposure. This approach considers disaggregate motor vehicle and cyclist flows and develops cyclist injury frequency models. Three definitions of risk exposure were used in this research, including aggregated flows, motor vehicle flows aggregated by movement type, and potential conflicts between motor vehicles and cyclists. As an application environment, a large sample of signalized intersections on the island of Montreal, Quebec, Canada, was used, along with data that comprised disaggregate motor vehicle and cyclist flows. Several negative binomial models were fitted to the data. This study showed that cyclist collisions were sensitive to changes in both cyclist and motor vehicle flows. A 10% increase in bicycle flow was associated with a 4.4% increase in the frequency of cyclist injuries. A 10% increase in the total number of motor vehicles that passed through the intersection would result in a 3.4% increase in cyclist injury occurrence. When motor vehicle flows were considered on the basis of movement type, right-turn movements had a great effect on injury occurrence. Similar results, which identified right turns as having the greatest effect on cyclist injuries, were produced when the impact of potential conflicts was determined. The number of bus stops in the proximity of the intersection increased cyclist injury occurrence. Some geometric design factors, such as the presence of a median, parking entrance, and the number of intersection legs, were tested. The effect, however, was found to be statistically nonsignificant.