International Journal of Transportation Science and Technology最新文献

Pedestrian crashes at high-speed locations are a persistent road safety concern. Driving at high speeds means that the driver has less time to react and make evasive maneuvers to avoid a pedestrian crash. On top of this, other crash-contributing factors such as humans (pedestrians or drivers), vehicles, roadways, and surrounding environmental factors actively interact together to cause a crash at high-speed locations. The pattern of pedestrian crashes also differs significantly according to the high-speed intersection and segment locations which require further investigation. This study applied association rules mining (ARM), an unsupervised learning algorithm, to reveal the hidden association of pedestrian crash risk factors according to the high-speed intersection and segments separately. The study used Louisiana pedestrian fatal and injury crash data (2010 to 2019). Any crash location with a posted speed limit of 45 mph or above is classified as a high-speed location. Based on the generated association rules, the results show that pedestrian crashes at a high-speed intersection are associated with the intersection geometry (3-leg) and control (1 stop, no traffic control device), driver characteristics (careless operation, failure to yield, inattentive-distracted, older, and younger driver), pedestrian-related factors (violations, alcohol/drug involvement), settings (open country, residential, business, industrial), dark lighting conditions and so on. Most pedestrian crashes at high-speed segments are associated with roadways with no physical separation, dark-no-streetlight conditions, open country locations, interstates and so on. The findings of the study may help to select appropriate countermeasures to reduce pedestrian crashes at high-speed locations.

In this paper, a meaningful representation of the road network using multiplex networks and a novel feature selection framework that enhances the predictability of future traffic conditions of an entire network are proposed. Using data on traffic volumes and tickets’ validation from the transportation network of Athens, we were able to develop prediction models that not only achieve very good performance but are also trained efficiently, do not introduce high complexity and, thus, are suitable for real-time operation. More specifically, the network’s nodes (loop detectors and subway/metro stations) are organized as a multilayer graph, each layer representing an hour of the day. Nodes with similar structural properties are then classified in communities and are exploited as features to predict the future demand values of nodes belonging to the same community. The results reveal the potential of the proposed method to provide reliable and accurate predictions.

Automated vehicles (AVs) hold great promise for creating a safer, more efficient, more equitable, and more sustainable transportation system. However, the rapid adoption of AVs requires a thorough understanding in their coexistence with the human environment in the current roadway network, particularly with respect to interactions between AVs and non-motorists. Bike Pittsburgh (BikePGH) conducted a 2019 survey to examine non-motorists' perceptions of AV safety. Using Bayesian network (BN) analysis, the study identified key factors such as safety perception, AV technology knowledge, and real-world interaction experiences that influence non-motorists' overall perception of AV safety using BikePGH survey data. The study also explored several counterfactual scenarios to gain insights into non-motorists' viewpoints on AV safety. Notably, the study found that the differences in the ways of AVs and human-driven vehicles interacted with non-motorists at intersections played a crucial role in shaping survey participants' opinions. By taking into account the key insights identified in this study, policymakers can develop evidence-based strategies to achieve sustainable urban mobility goals while ensuring the safety and well-being of all road users, particularly non-motorists.

Paratransit users have reportedly been unsatisfied with the quality of service that they receive. Efforts at replacing the service or formalizing operations to meet users’ mobility needs have faced challenges or outrightly resisted. Approaches such as providing travel information and deploying interventions along the roadway infrastructure where the government has authority have been suggested. Deploying any of these approaches will require insights from empirical data. The study considered a key measure of service quality to users and operators alike – travel time. It investigated factors affecting the travel time of paratransit at the route and segment levels. A travel time survey that employed a mobile app (Trands) onboard paratransit vehicle was used to collect travel time, stop, and other related information on a selected route. The backward stepwise regression technique was used to determine factors affecting paratransit travel were. Dwell time, signal delay, recurrent congestion index (RCI), non-trip stops, and deviation from route were significant variables at the route level. All the factors affecting segment travel were also part of those involving route travel time except the segment length. Interestingly, deviation from the route increased overall travel time, which is against its logic. Insights gained from the study were used in suggesting proposals that can reduce travel time and improve the service quality of paratransit.

Road pavement surfaces need routine and regular monitoring and inspection to keep the surface layers in high-quality condition. However, the population growth and the increases in the number of vehicles and the length of road networks worldwide have required researchers to identify appropriate and accurate road pavement monitoring techniques. The vibration-based technique is one of the effective techniques used to measure the condition of pavement degradation and the level of pavement roughness. The consistency of pavement vibration data is directly proportional to the intensity of surface roughness. Intense fluctuations in vibration signals indicate possible defects at certain points of road pavement. However, vibration signals typically need a series of pre-processing techniques such as filtering, smoothing, segmentation, and labelling before being used in advanced processing and analyses. This research reports the use of noise-cancelling and data-smoothing techniques, including high pass filter, moving average method, median, Savitzky-Golay filter, and extracting peak envelope method, to enhance raw vibration signals for further processing and classification. The results show significant variations in the impact of noise-cancelling and data-smoothing techniques on raw pavement vibration signals. According to the results, the high pass filter is a more accurate noise-cancelling and data smoothing technique on road pavement vibration data compared to other data filtering and data smoothing methods.

Left turn traffic at unsignalized T-intersection on undivided rural two-lane high-speed highways poses both operational and safety challenges. More complexities are faced by through drivers in the same direction as the stopped or slowed down left-turn vehicle must choose to either slow down and wait or bypass the left-turn vehicle. Therefore, this study intends to explore the operational characteristics of these facilities. The focus is on the reaction of the drivers behind the left-turn vehicle in terms of the types of maneuvers taken to avoid collision and the distance upstream for the evasive maneuvers using field observations. Further, the impact of the drivers’ reaction on the intersection delay is assessed using a simulation analysis of 17 generic 10.5-mile two-lane corridors with varying configurations of passing lanes at or near the intersection with and without a left-turn lane. The field observation findings from five sites reveal that drivers will move to the shoulder to avoid slowing and stopping or colliding with the left-turn vehicle. The distance at which drivers move to the shoulder differs for the sites studied. The simulation results show that a relatively similar magnitude of reduction in intersection delay could be achieved by addition of either passing lane or left-turn lane, such addition is beneficial for at least 17 000 vpd intersection volume where the passing lane does not end within 1 500 ft is downstream of the intersection. The findings are expected to improve traffic operations at T-intersections on rural two-lane highways.