scholarly journals A Series of Vertical Deflections, a Promising Traffic Calming Measure: Analysis and Recommendations for Spacing

2020 ◽  
Vol 10 (10) ◽  
pp. 3368 ◽  
Author(s):  
Heriberto Pérez-Acebo ◽  
Robert Ziółkowski ◽  
Alaitz Linares-Unamunzaga ◽  
Hernán Gonzalo-Orden

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.

2017 ◽  
Vol 43 (3) ◽  
pp. 29-42 ◽  
Author(s):  
Stanisław Gaca ◽  
Sylwia Pogodzińska

The article presents the issue of the implementation of speed management measures on regional roads, whose character requires the use of different solutions than those on national roads. The authors briefly described speed management measures, the conditions for their implementation and their effectiveness with reference to environmental conditions and road safety. The further part of the paper presents selected results of the authors' research into the speed on various road segments equipped with different speed management measures. The estimations were made as to the impact of local speed limits and traffic calming measures on drivers' behaviour in free flow conditions. This research found that the introduction of the local speed limits cause reduction in average speed and 85th percentile speed up to 11.9 km/h (14.4%) and 16.3 km/h (16.8%) respectively. These values are averaged in the tested samples. Speed reduction depends strongly on the value of the limit and local circumstances. Despite speed reduction, the share of drivers who do not comply with speed limits was still high and ranged from 43% in the case of a 70 km/h limit, up to 89% for a 40 km/h limit. As far as comprehensive traffic calming measures are concerned, results show decrease in average speed and 85th percentile speed up to 18.1 km/h and 20.8 km/h respectively. For some road segments, however, the values of average speed and 85th percentile speed increased. It confirms that the effectiveness of speed management measures is strongly determined by local circumstances.


Author(s):  
Hernán Gonzalo Orden

In recent years the number of deaths and serious injuries is decreasing in Spain, but, although the reduction outside the cities has been very strong, inside the urban areas, it has been smaller. This is especially hard if you look at the most vulnerable road users such as pedestrians and cyclists. In many accidents the speed factor appears closely linked not only to the number, but also to the severity of the accidents suffered inside the urban areas. Therefore, a reduction in the speed would improve the road safety. There are different measures known as "traffic calming measures" whose objectives are to reduce both the number and severity of accidents that occur on urban areas, by reducing the traffic flow through the streets, as well as the speed of the vehicles. However, the efficiency in speed reduction of each measure is not entirely known. That's the reason why they are implanted, in many cases, with no technical basis. The aim of this article is to show the effectiveness in reducing speed of some of the traffic calming measures. To this effect, field measurements were done on street sections with different types of traffic calming measures, in different places of a city of Burgos, in the north of Spain. These measurements were compared with other ones sited on other streets sections of similar characteristics but without traffic calming measures. Finally the conclusions are shown and some recommendations for improving their effectiveness are given.DOI: http://dx.doi.org/10.4995/CIT2016.2016.4217


2021 ◽  
pp. 167-177
Author(s):  
Andreas Höfer ◽  
Erhard Esl ◽  
Daniel Türk ◽  
Veronika Hüttinger

AbstractIn megacities, increasing globalization effects are leading to rapidly increasing prosperity and augmented purchasing power, and thus to a growing need for punctual, cost-effective, and environmentally friendly delivery of goods. A smart, small electric vehicle concept is presented that targets on meeting the requirements for the delivery of goods in urban areas and that is designed especially for the delivery on the last mile. This last mile vehicle (LMV) for cargo transportation is attached to a truck. Whenever it is needed, for example to deliver goods into narrow streets, in pedestrian areas or in case of traffic jams, it can be unfolded and unloaded from the truck and hereby guarantees a flexible and punctual delivery of goods. This flexible on-time delivery is possible because the last mile vehicle is designed, so that the legal regulations of the non-motorized vehicle lane, that is everywhere to be found in Asia, are met. The vehicle is designed with three wheels, a range of 40-60 km and an electric drive train with a continuous power of 2 × 250 W that enables a maximum speed up to 40 km/h of the vehicle. The drive train consists of a battery pack that can be charged electrically from the truck, two inverters, and two electric wheel hub motors. The LMV has been designed and constructed as a prototype and has been tested on non-public roads to prove the vehicle concept. For Europe, it can be classified as an L2e vehicle and with slight modifications; it can be applied on European roads as well.


2021 ◽  
Vol 72 (12) ◽  
pp. 1131-1143

Increasing numbers of people living in urban areas are being exposed to harmful action of environmental noise, which severely affects their health and quality of life. The predominant source of environmental noise in such areas is road traffic, and a frequently used measure to curb down this noise involves reduction of driving speed. The influence of vertical traffic calming devices, normally used to improve traffic safety, on the degree of noise reduction, is analysed in this study. The analysis was carried out on seven urban two-lane two-way roads, on which various types of speed bumps and speed humps are installed.


Author(s):  
Sheila Sarkar ◽  
A. A. Jan Nederveen ◽  
Albert Pols

Success of road design depends to a large extent on how safe it is for different users. Unfortunately, in most instances the definition of road users in the United States has precluded pedestrians and bicyclists. Safety of pedestrians and bicyclists is most often relegated to a marginal status in many parts of the urban areas. The roads in the past few decades, with a few exceptions, were built for speed, ensuring maximum convenience to drivers, but, intimidating the green modes (pedestrians and bicyclists). Traffic calming is one way of reclaiming the roads for a more equitable use by different users. Many European countries have been successful in giving back the road to the pedestrians and bicyclists by implementing areawide traffic management and speed-reduction measures. The United States, however, is far behind these countries in actual implementation of such concepts, although thinking on these lines had started as early as the 1960s. There is a strong argument in favor of traffic calming in the United States based on facts and figures on accidents, road conditions, and driver behavior. In addition, field research in some European countries reveals the positive attributes of these planning principles and designs.


Author(s):  
Vinod Vasudevan ◽  
Aniruddha Rajurkar ◽  
Rahul Soni ◽  
Akhil Tiwari

Traffic safety is a major concern across the world. Since speed is a major cause of traffic crashes, various traffic calming measures are used to enhance the safety of the road users in urban areas. Speed humps and bumps are the most widely used traffic calming devices. As a considerable number of bicyclists use the road along with motorized users, it is important to consider them while deploying any traffic calming devices. Studies have shown that bicyclists experience significantly larger discomfort as compared to motorized vehicles while passing over speed humps. In this study, a modification has been proposed to enhance riding comfort of bicyclists without compromising the traffic calming attribute of a speed bump. This modification is named “K-pass.” Analysis of data collected before and after the modification justifies the effectiveness in reducing the discomfort of bicyclists. Over a period of eight months, 70% of the bicyclists chose to use K-pass. Data also revealed that a high proportion of motorized two-wheeler users also used the K-pass at reduced speeds. It is expected that the K-pass will be a useful modification to the existing speed humps and speed bumps in areas where bicycle usage is expected.


Author(s):  
Ali Kamyab ◽  
Steve Andrle ◽  
Dennis Kroeger ◽  
David S. Heyer

Many Minnesota counties are faced with the problem of high vehicle speeds through towns or resort areas that have significant pedestrian traffic. The impact of speed reduction strategies in high-pedestrian areas in rural counties of Minnesota was investigated. Speed data were collected at two selected study sites under their existing conditions ("no-treatment" or "before" condition) and after the proposed speed reduction strategies were installed. Second "after" data conditions were collected to study the short-term and long-term impact of the implemented strategies. The traffic-calming techniques employed at the Twin Lakes site consisted of removable pedestrian islands and pedestrian crossing signs. A dynamic variable message sign that sent a single-word message ("Slow") to motorists traveling over the speed limit was installed at the Bemidji site. The research study shows that the traffic-calming strategy deployed in Twin Lakes was effective in significantly reducing the mean speed and improving speed limit compliance in both the short term and long term. Despite proven effectiveness, the deployed speed reduction treatment in Bemidji Lake failed to lower the speed at the study site. The single-word message on the sign and the location of the sign, as well as a lack of initial enforcement, were the primary reasons for such failure.


2016 ◽  
Author(s):  
Yunfei Wu ◽  
Xiaojia Wang ◽  
Jun Tao ◽  
Rujin Huang ◽  
Ping Tian ◽  
...  

Abstract. Black carbon (BC) plays an important role in the climate and environment due to its light absorption, which is greatly dependent on its physicochemical properties including morphology, size and mixing state. The size distribution of the refractory BC (rBC) in urban Beijing during the late winter in 2014 was revealed by measurements obtained using a single particle soot photometer (SP2), when the hazes occurred frequently. By assuming void-free rBC with a density of 1.8 g cm−3, the mass of the rBC showed an approximately lognormal distribution as a function of the volume-equivalent diameter (VED), for which there was a peak diameter of 213 nm. This size distribution agreed well with those observed in other urban areas of China. Larger VED values of the rBC were observed during polluted periods than on clean days, implying an alteration in the rBC sources, as the mass-size of the rBC from a certain source varied little once it was emitted into the atmosphere. The potential source contribution functions showed that air masses from the south to east of the observation site brought a higher rBC loading with more thick coatings and larger core sizes. The mean VED of the rBC (VEDrBC) presented a significant linear correlation with the number fraction of thickly coated rBC (NFcoated); the VED of the entirely externally mixed rBC was inferred as the y-intercept of the linear regression. This VED, with a value of ~150 nm, was considered as the typical mean VED of the rBC from local traffic sources in this study. Accordingly, the contribution of the local traffic to the rBC was estimated based on reasonable assumptions. Local traffic contributed 35 to 100 % of the hourly rBC mass concentration with a mean of 59 %, during this campaign. A lower local traffic contribution was observed during polluted periods, suggesting increasing contributions of other sources (e.g., coal combustion/biomass burning) to the rBC. The heavy pollution in Beijing was greatly influenced by other sources in addition to the local traffic.


2018 ◽  
Vol 181 ◽  
pp. 04002
Author(s):  
Leksmono Suryo Putranto ◽  
Kevin Kurniawan

To reduce potential pedestrian fatalities, in residential road maximum speed is 30km/hour. Apart from installing maximum speed signs, installing road humps may ensure speed reduction. This paper is intended to compare light vehicles and motorcycles speeds and speeds reductions due to road humps. Data collection was done in Modernland, Tanggerang City. Two road segments were observed, i.e. segments with standard and non-standard road humps. Observation was made in morning, noon and afternoon periods. A portable speed gun was used to measure the speed at about 50m and 25m before the road humps. Some mean difference statistical analyses were conducted for both speeds and speeds differences between different type of road humps and between pairs of observation periods. The 0.05 significant level was used. Surprisingly, mean of speeds differences (50m vs 25m) in standard road hump is significantly higher than in non-standard road hump.


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