Because speeding is one of the most significant contributing factors to fatal crashes, most road agencies attempt to achieve the right operating speed by imposing speed limits. Speed limit violations are prevalent, even on motorways with speed cameras. A problem with speed camera enforcement is that some motorists brake before passing a camera location and then exceed the speed limit after passing. This sudden braking can cause dangerous situations, crashes, and traffic jams. Furthermore, safe operating speed is not achieved where there are no cameras, especially where enforcement is overt, as in Italy. A new technique to overcome these problems is an automated section speed enforcement system, Safety Tutor. Unlike conventional speed meters, which measure vehicle speed at one point, the new technique determines average speed over a long distance. This study evaluated the safety effectiveness of the Safety Tutor system installed on Italian Motorway A1 Milan–Naples in 2007. An empirical Bayes observational before-and-after study was performed. The estimate of the total crash reduction is 31.2%, with a lower 95% confidence limit of 24.3%. The greatest crash reductions were observed for severe crashes and crashes at curves. Reduction was 55.6% for severe crashes, 26.6% for nonsevere crashes, 43.4% at curves, and 28.4% at tangents. However, the system's effectiveness decreased over time. The crash reduction was 39.4% in the first semester after the system's activation and 18.7% in the fifth semester after activation. Results strongly support activation of the new automated system owing to highly significant and substantial safety effects. The decrease in system effectiveness over time may be correctible with higher levels of enforcement.

Background: Since the beginning of the new millennium, sensitivity towards the environment has been spreading globally. In fact, countries are adopting measures to develop new decision support tools that can evaluate the impact of interventions to promote and encourage sustainable mobility. To reduce the levels of pollution related to road traffic, policies that favor multimodal transport alternatives have been strengthened. This involves the combined use of public transport, cycling and walking paths, as well as sharing services where available. Regardless of the type of transport, the pedestrian component remains relevant in cities, even if the infrastructures are often not adequate to accommodate it and conflicts arise that must be managed. It is, therefore, necessary to assess the exposure to risk in terms of road safety. Methods: To this end, the work proposes a forecasting model to estimate the pedestrian flows that load the network. The methodology employs a hybrid approach that appears to better capture the movements of pedestrians. Results: By comparing the results of the model with the real data collected on the study area, satisfactory estimates were obtained. Conclusions: Therefore, this can be an effective tool to help road managers to evaluate the actions to protect vulnerable users.

This paper deals with the experimental measurements and numerical predictions of vibrations produced by underground railways, which propagate through the subsoil up to the ground surface. Two test sites were chosen along the new underground railways in Turin and Naples, which are representative of light and heavy railway transit systems, respectively. The vibrations generated by the railway operations were experimentally characterized by monitoring train transits across selected sections. Arrays of velocimeters were placed on the railway tracks and on the ground surface, and, for the case of Naples, also along a 30 m deep borehole. Up-to-date techniques for data acquisition and processing allowed identifying significant records in terms of peak amplitudes and frequency content. The vibrations recorded at the source allowed one to calibrate the analytical modelling of the dynamic interaction between the rolling stock and the railway, taking into account the inertia of vehicles, the track roughness and the mechanical properties of the superstructure. Surface and borehole geophysical tests made it possible to define horizontally layered visco-elastic models of the subsoil at both the selected test sites. The numerical simulation of the ground propagation of vibrations was carried out using a 2D finite difference code (FLAC 5.0), with the experimental record at the track level as kinematic input motion at the inner boundary of the tunnel. The results of the analyses were processed in terms of peak amplitudes at variable depths and on the surface; these latter values were compared with experimental records and threshold levels suggested in international standards. Copyright © 2008 John Wiley & Sons, Ltd.

With increasing emphasis on new soft mobility in urban areas, it becomes more and more important to provide effective speed control measures for vehicular traffic. Among those, the ones based on vehicle vertical deflection, namely vertical traffic calming measures, are historically the most widespread. However, since the basic operating principle of these devices is related to the vertical dynamic response due to the interaction between the moving vehicle and the road profile, different vehicles may exhibit different speed behaviors when traveling on a specific road profile shape. As a matter of fact, recent research provided evidence of this connection, and therefore it has been worth investigating the dynamics underlying the phenomenon in order to develop a new approach to the design of vertical traffic calming devices. In this paper, following an initial state-of-the-art review, an in-depth study on the dynamic interaction between vehicle and road profile has been presented by means of an ad hoc-developed mathematical model. The proposed simulation model has been used to evaluate the root mean square acceleration value associated with each vehicle/traffic calming device/crossing speed. Following the outcomes provided by numerical simulations, an experimental investigation has been designed and carried out on a vertical traffic calming device. Speed profiles of different vehicles have been acquired, and preliminary results seem to provide evidence of a different dynamic response for each vehicle type, yielding the basis to reconsider the design approach of such devices in order to control urban traffic speed.