Traffic calming measures (TCM) are placed in urban areas to improve road safety, and among them, vertical TCMs are widely employed. Many researches are focused on the influence of the geometry of each measure on speed reduction, but it is demonstrated that drivers forget its effect and speed up after it. Therefore, placing consecutive TCMs can help to maintain a safe area. However, scarce literature can be found about the adequate spacing between them. Hence, the aim of this paper is to analyze the adequate distance between TCMs. Various streets with variable distances and different vertical TCMs were evaluated in Poland and Spain, including raised crosswalks, raised intersections, speed humps and speed cushions. The intermediate point between two TCMs was selected as the place where the maximum speed is achieved. Results showed that there was a good correlation between the speeds at intermediate points and the distance between TCMs, with a determination coefficient around 0.80. For an 85th percentile of the speed under 50 km/h, a maximum distance of 200 m between TCMs is recommended, and for a value of 40 km/h, 75 m.

Driving speed remains within the most important factors in road safety, and speed not only affects the severity of a crash but is also related to the risk of being involved in a crash. Inappropriate speed is responsible for more than a third of all fatal accidents occurring on roads. In Poland the problem of speeding drivers is widely present. Hence, effective speed management and enforcement of speed limits on existing roads plays an important role. Possible solutions for rural roads are very limited and are focused mainly on administrative speed limitations and speed cameras enforcement. However, due to their limited effectiveness new solutions are still being sought. High expectations are associated with the automatic section speed control system that has recently been introduced in Poland. The aim of this paper is to examine the efficiency of the automatic section speed control system on the basis of speed surveys collected on chosen national roads where the system for sectional speed control was first implemented. Conducted comparisons and statistical analyses included driver's average speed, speed percentiles, the number of speeding drivers as well as speed heterogeneity. To evaluate the efficacy of the sectional speed system, speed measurements were also conducted on fourteen, similar in geometry and functional characteristics, reference national roads located in Podlaskie voivodship in Poland without any specific speed enforcement. KEY WORDStraffic management; section speed control; excessive speed; heterogeneity of speed; Change in accident/injury rate [%] Change in speed [%] All accidents Fatalities Light injuries 100.0

Driving speed is one of the most important factors in road safety, and speed not only affects the severity of a crash, but is also related to the risk of being involved in a crash. Inappropriate speed is responsible for more than a third of all fatal accidents occurring on the roads. In Poland, the problem of speeding drivers is widely common. Hence, effective speed management and enforcement of speed limits on existing road plays an important role. Possible solutions for rural roads are very limited and have focused mainly on administrative speed limitations and speed cameras enforcement. However, due to their limited effectiveness, new solutions are still being sought. High expectations are associated with the latest introduction of sectional speed system in Poland. The aim of this paper is to examine the efficiency of the sectional speed control system implemented on chosen sections of national roads in Podlaskie province. For this purpose, speed surveys included road segments where the system for sectional speed control had been already implemented, as well as in order to evaluate its effectiveness, speed measurements were conducted on other national roads with no further specific restrictions. In addition, to evaluate the possible influence of the sections monitored by the system on driver's behaviour on adjacent segments, the relevant speed data was collected on adherent sectors. On the basis of the conducted measurements, high effectiveness of sectional speed control system was stated together with its impact on adjoining segments, but also some deficiency in terms of speed homogeneity has been revealed.

Traffic calming measures (TCMs) are implemented in urban areas to reduce vehicles’ speed and, generally speaking, results are obtained. However, speed is still a problem in rural roads crossing small villages without a bypass and with short-length urban areas, since drivers do not normally reduce their speed for that short segment. Hence, various TCM can be installed. It is necessary to maintain a calm area in these short segments to improve road safety, especially for pedestrian aiming to cross the road, and to save combustible by avoiding a constant increase-decrease of speed. Four villages were selected to evaluate the efficiency of radar speed cameras and panels indicating vehicle’s speed. Results showed that the presence of radar speed cameras reduces the speed in the direction they can fine, but with a lower effect in the non-fining direction. Additionally, a positive effect was observed in the fining direction in other points, such as pedestrian crossings. Nevertheless, the effect does not last long and speed cameras may be considered as punctual measures. If the TCMs are placed far from the start of the village they are not respected. Hence, it is recommended to place them near the real start of the build-up area. Lastly, it was verified that longer urban areas make overall speed decrease. However, when drivers feel that they are arriving to the end of the urban area, due to the inexistence of buildings, they start speeding up.

Purpose – Under deteriorating conditions of travelling in urban areas, especially city centers, prioritization of public transport is one of the main ways of its enhancing. In developed countries sophisticated control traffic systems are being implemented while in developing countries such solutions due to implementation cost are very rare. The purpose of this paper is to assess public transport operational effectiveness under diverse operational schemes present in two similar in size and traffic characteristics cities. The assessment is based on average journey times and speeds during peak and off peak hours. Design/methodology/approach – The methodology includes measurements and estimates of bus rides through in-field measurements in Edinburgh, UK and in Bialystok, Poland. In-field evaluations have been conducted using average speed and travel times. The data were collected by utilizing a portable GPS data logger that allowed monitoring and recording bus position along tested streets in one second intervals. Traffic optimization in Edinburgh is provided by separated bus lanes and control urban traffic system while in Bialystok the only prioritization is supported by bus lanes. The research areas in Edinburgh and in Bialystok covered streets in city centers and adjacent districts. Findings – The findings show large operational potential in developing separated bus lanes in city centers of developing countries when due to cost they cannot afford implementing advanced ITS solutions. The introduction of bus lanes should be proceeded even at the expense of individual users. It has been found that well developed road network in city center with separated bus lanes can provide operating speed at comparable levels to speed of buses operating along lower volume corridors. Originality/value – The comparison of bus lanes working under different traffic management conditions was carried out. Conducted analyses showed great potential of proper planning strategy of road network development toward the improvement of public transport performance.