Major Arterial Roadways Research Articles

Enhancing Health through Built Environment Improvement: A Southern Nevada Health Impact Assessment Case Study

Background: Health Impact Assessment (HIA) is a public health tool to evaluate how choices made outside the health sector can affect health. HIAs are utilized in transportation, housing, planning, and other fields. Since the built environment can impact community health outcomes, including physical activity rates, injuries, and overweight and obesity, an interdisciplinary team composed of public health, planning, transportation, and land use professionals conducted an HIA in Las Vegas, Nevada.
 Methods: The HIA consisted of (1) screening, (2) scoping, (3) assessment, (4) recommendations, (5) reporting, and (6) monitoring and evaluation. It examined proposed physical improvements to a 0.66 mile stretch of a major arterial roadway in the City of Las Vegas where nearby residents experience many health inequities. Collection and analysis of land use and survey data, analysis of secondary data, and literature reviews were completed to predict potential health effects produced by built environment changes. Stakeholder feedback informed each HIA step.
 Results: The HIA generated recommendations to improve physical activity, reduce pedestrian and bicyclist injury rates, and decrease obesity and overweight prevalence, by presenting “good,” “better,” and “best” physical infrastructure improvements. The process and resulting recommendations enhanced collaboration among health and nonhealth sectors.
 Conclusions: Data and analysis revealed that the proposed changes could improve walkability and bikeability and reduce pedestrian and bicyclist injury. By encouraging active transportation through bicycling and walking, the plan could, over time, contribute to reduced overweight and obesity. The HIA facilitated inter-sector cross collaboration and the integration of health into future decision-making.

Estimating the effect of vehicle speeds on bicycle and pedestrian safety on the Georgia arterial roadway network

Cyclists and pedestrians account for a disproportionate amount of the world’s 1.3 million road deaths every year. This is a growing problem in the United Sates where bicyclist and pedestrian fatalities have increased steadily since 2009. A large body of research suggests vehicle speeds are a key contributing factor for crashes. However, few studies of bicycle or pedestrian crash probability incorporate detailed vehicle speed data.This study uses probe vehicle speed data to examine the impact of vehicle speeds on bicycle and pedestrian crashes on the state of Georgia’s network of major arterial roadways. The analysis examines 7000 road segments throughout the state in 2017. A Negative Binomial model relates annual crash and speed data on each segment. Models using speed percentiles (85th, 50th and 15th) are contrasted with models using speed differences (85th–50th and 50th–15th percentile). A small set of covariates are included: segment length, number of lanes, Average Annual Daily Traffic, and urbanicity.Results indicate that larger differences in high-end speed percentiles are positively associated with bicycle and pedestrian crash frequency on Georgia arterials. Furthermore, the coefficients on the high end of the speed distribution, measured by the difference in 85th and 50th percentile speeds, have greater magnitude and statistical significance than the low end of the distribution. This research shows a negative relationship between speed and crashes may be flawed, as it does not account for the distributions of speed.The findings in this study suggest that planners and engineers should identify areas with large speed distributions, especially at the high vehicle speeds, and work to reduce the fastest speeds on these roadways. To do so, differences in speed percentiles measured using probe vehicle speeds can be used to determine where high risk areas are located.

Investigation of ambient noise, surface quality improvements, and friction characteristics of different asphalt surfaces in Alberta, Canada

To determine how pavement noise and grip may be affected by pavement treatment type, a test section was constructed on a major arterial roadway in St. Albert, Alberta. This test section was used to compare the noise and friction differences of a microsurfacing layer, stone mastic asphalt (SMA), and high traffic asphalt (HT) utilizing an onboard sound intensity (OBSI) device, roadside noise meters, and a grip tester. The results of the grip tests revealed that SMA and HT had little effect on improving friction in the corridor, while microsurfacing improved the corridor grip by 15%. From noise testing, it was found that HT provided the best immediate noise attenuation compared to SMA and microsurfacing.

Impact of an automated road debris removal system on traffic flow using VISSIM

This study introduces a state-of-the-art road debris removal system (i.e., automated road debris removal system (ROBOS)) and analyzes its impact on traffic flow using the microscopic simulation model, VISSIM. Robust simulation scenarios were established, and the major parameters of individual scenarios were also included based on extensive interviews with road workers. The performances of road workers and the ROBOS in regard to road debris removal were investigated in terms of four measures of effectiveness. These included queue, density, percentage delay, and number of vehicle stops. To mimic the major arterial roadways in South Korea, two-lane, three-lane, and four-lane roads were considered for implementing the road debris removal process. The simulation results as well as the statistical analysis revealed that the ROBOS outperforms the direct removal by road workers in all aspects. Thus, the ROBOS can remove the debris more safely and efficiently. The findings of this research can improve institutional operational guidelines for the ROBOS by providing an appropriate range for its parameters. This can result in enhancing traffic safety and efficiency. Notwithstanding the simulation results, the more unexpected cases, such as the driver carelessness during removal work, should be reflected in future research to thoroughly prevent the potential risk of accidents as well as maintaining smooth traffic flow.

H-CTM for simulating non-lane-based heterogeneous traffic

This paper developed a first-order deterministic macroscopic model H-CTM (heterogeneous cell transmission model) based on basic cell transmission model (CTM). The methodological calibration of the model considers the aggregate behavior of heterogeneous traffic under weak lane discipline. H-CTM incorporates a nonlinear fundamental diagram (FD), modeled for non-lane-based heterogeneous traffic, instead of traditional piecewise linear FD. For validating the model performance, high resolution traffic data were collected from a major arterial roadway (N3-Highway) of Dhaka city covering both peak and off-peak periods. Subsequently, the calibrated FD parameters were incorporated in the newly developed H-CTM to simulate the traffic. The estimated traffic states by the proposed model were then compared with basic model of CTM. Model performances, calculated in terms of mean absolute error based on ground truth values show that the H-CTM can be used to describe the traffic dynamics in the stated traffic system better than the basic model.

Evaluation of a high efficiency cabin air (HECA) filtration system for reducing particulate pollutants inside school buses.

An increasing number of studies have reported deleterious health effects of vehicle-emitted particulate matter (PM), including PM2.5 (aerodynamic diameter≤2.5 μm), black carbon (BC), and ultrafine particles (UFPs, diameter≤100 nm). When commuting inside school buses, children are exposed to high level of these pollutants due to emissions from both school bus itself and other on-road vehicles. This study developed an on-board high efficiency cabin air (HECA) filtration system for reducing children's exposure inside school buses. Six school buses were driven on two typical routes to evaluate to what extent the system reduces particulate pollutant levels inside the buses. The testing routes included freeways and major arterial roadways in Los Angeles, CA. UFP number concentrations and size distributions as well as BC and PM2.5 concentrations were monitored concurrently inside and outside of each bus. With the HECA filtration system on, in-cabin UFP and BC levels were reduced by 88±6% and 84±5% on averages across all driving conditions, respectively. The system was less effective for PM2.5 (55±22%) but successfully kept its levels below 12 μg/m3 inside all the buses. For all three types of particulate pollutants, in-cabin reductions were higher on freeways than on arterial roadways.

Cluster analysis of roadside ultrafine particle size distributions

This study reports the diurnal, seasonal, and annual variation of ultrafine particle size distributions in downtown Toronto. The k-means clustering algorithm was applied to five years of size-resolved data for particles with diameters less than 100 nm. Continuous particle number concentrations were measured 16 m from a major arterial roadway between March 2006 and May 2011 using a Fast Mobility Particle Sizer. Eight particle size distribution (PSD) types were identified. The PSD types exhibited distinct weekday–weekend and diurnal patterns. The relative frequency that each PSD occurred varied with season and wind direction and was correlated with other pollutants. These temporal patterns and correlation helped in elucidating the sources and processes that each of the eight PSD represent. Finally, similar PSD types were observed in residential areas located 6 and 15 km away from the central monitoring site suggesting that these PSD types may be generalizable to other sites. Identification of PSD types was found to be a valuable tool to support the interpretation of PSD data so as to elucidate the sources and processes contributing to ultrafine particle concentrations.

Effect of residential proximity to major roadways on cystic fibrosis exacerbations

Ambient air pollution has been attributed with an increase in exacerbation frequencies among the cystic fibrosis (CF) population. This study correlates exacerbation frequency with proximity to roadways and two criteria air pollutants. Clinical data was extracted from the Cystic Fibrosis Foundation National Patient Registry and Electronic Medical Records at Children's Hospital Los Angeles (CHLA). Average annual air pollutant levels were obtained from selected US Environmental Protection Agency's monitoring stations. Geographic proximity to monitoring stations and roadways were analyzed using spatial mapping software. A total of 145 patients from the CHLA's CF center were characterized by a dichotomous exacerbation category. No significant association was determined between the frequency of exacerbations and exposure to fine particulate matter and ozone levels. Residential proximity to US-designated highways and freeways also did not achieve significance (p = 0.3777) but was noted to be correlated with major arterial roadways (p = 0.0420). Associations of environmental exposures may have important implications for future predictive models of CF clinical outcomes.

Five-year roadside measurements of ultrafine particles in a major Canadian city

Abstract This study reports the diurnal, seasonal and annual variation of ultrafine particles (UFP) in a large city. Particle number (PN) concentrations were measured in Toronto, Canada on a major arterial roadway between March 2006 and May 2011 using a Fast Mobility Particle Sizer. The PN in the size range of 8–300 nm decreased during the measurement period primarily due to changes in the vehicle fleet. PN 50 (particles with diameters less than 50 nm) decreased by 21% between 2006 and 2010. Notably, the majority of the reduction occurred during the winter months. PN 50 exhibited the strongest seasonality and diurnal trend. PN 50–100 (particles between 50 and 100 nm) and PN 100–300 (particles between 100 and 300 nm) decreased by 17% and 24%, respectively. Correlation analysis between gas phase criteria pollutants showed good correlation between PN 50–100 and NO 2 , SO 2 , and PM 2.5 . In contrast, PN 50 exhibited the highest correlation with temperature, NO and NO 2 . A multiple linear regression model was developed for each size fraction. The model adequately explained the annual, seasonal and day-to-day variability of PN 50–100 ( R 2 = 0.64) and PN 100–300 ( R 2 = 0.83). The model captured the annual and seasonal variability of PN 50 but only partially explained the day-to-day variability ( R 2 = 0.52). The long-term reductions in PN 50 indicate that policy interventions are having some success in slowly decreasing UFP concentrations in Toronto.

Investigation of the Dayton, Ohio, IR 75 Sign Truss Failure of September 11, 2006

On September 11, 2006, “unusual” deflections of an overhead bridge-mounted sign support truss along IR 75 in Dayton, Ohio were reported. Investigation by Ohio DOT road crews revealed the complete fracture of two truss members near one of the truss supports. While total collapse did not occur, such an event could have catastrophic consequences along a major arterial roadway like IR 75. This concern, along with the fact that a similar failure occurred near Cleveland, Ohio in 2004, prompted an investigation that is the subject of this manuscript. Results of the investigation are based upon a combination of in situ field monitoring of traffic-induced bridge vibrations at the location of the failed sign support truss, finite-element simulation of the expected dynamic response of the original truss in such an environment, the length of service of the truss at the time of its failure, the volume of truck traffic on the bridge in question during that time of service, and metallurgical examination of the failed co...