scholarly journals Geometrical and Functional Criteria as a Methodological Approach to Implement a New Cycle Path in an Existing Urban Road Network: A Case Study in Rome

2018 ◽  
Vol 10 (8) ◽  
pp. 2951 ◽  
Author(s):  
Paola Di Mascio ◽  
Gaetano Fusco ◽  
Giorgio Grappasonni ◽  
Laura Moretti ◽  
Antonella Ragnoli

Most road accidents occur in urban areas and notably at urban intersections, where cyclists and motorcyclists are the most vulnerable. In the last few years, cycling mobility has been growing; therefore, bike infrastructures should be designed to encourage this type of mobility and reduce motorized and/or private transport. The paper presents a study to implement a new cycle path in the existing cycle and road network in Rome, Italy. The geometric design of the new path complies with Italian standards regarding the technical characteristics of bicycle paths, while the Highway Capacity Manual has been considered for the traffic analysis. In particular, a before-after approach has been adopted to examine and compare the traffic flow at more complex and congested intersections where the cycle path will pass. Trams, buses, cars, bikes and pedestrians were the traffic components considered in each analysis. The software package PTV VISSIM 8 allowed the simulations of traffic flows at traffic-light intersections; an original linear process has been proposed to model dynamic intelligent traffic controls, which are not admitted by the software used. The traffic analysis allowed the identification of the best option for each of the five examined intersections. Particularly, the maximum queue length value and the total number of passed vehicles have been considered in order to optimize the transport planning process. The results of this study highlight the importance of providing engineered solutions when a cycle path is implemented in a complex road network, in order to avoid negative impacts on the citizens and maximize the expected advantages.

2009 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Chen K.C. ◽  
Larry S.T.

The concept of Level of Service (LOS) is originated from the Highway Capacity Manual (HCM). LOS is a qualitative assessment of the operational performance of a roadway facility based on quantitative performance measures. Many transportation infrastructure funding decisions are based on LOS analysis, and LOS designations are intended to represent user-perceived quality of service. This study has been carried out to determine the LOS on different roads. The profile of study area is in Kuching, Sarawak where five roads with different characteristics and posted speed of urban multilane with 80km/hr and 70km/hr, suburban two-lane two-way with 90 km/hr and 80km/hr had been selected for the studies. Substantial numbers of inputs are required for the LOS analysis and determination based on HCM procedures. These inputs are: a long list of traffic volume collected in different peak hours; traffic composition such as proportion of heavy vehicles in traffic; geometric characteristics such as number of lanes, lane width, shoulder width, and approach grades. Results of the study showed that LOS in the urban multilane is still in satisfactory range with LOS ranging from C to D except for most of the traffic congestion cases in urban multilane at the traffic light junctions and roundabouts. However, LOS in the suburban two-lane two-way is only satisfying in the range of LOS E; hence multilane should be introduced in such cases. Recommendations such as to provide various or multitude modes of transportation needs should be introduced in urban area. Furthermore, a suitable and efficient hierarchy in road system should be provided in suburban areas before turning into urban areas.


Author(s):  
Mustapha Kabrane ◽  
Salah-ddine Krit ◽  
Lahoucine El Maimouni

In large cities, the increasing number of vehicles private, society, merchandise, and public transport, has led to traffic congestion. Users spend much of their time in endless traffic congestion. To solve this problem, several solutions can be envisaged. The interest is focused on the  system of road signs: The use of a road infrastructure is controlled by a traffic light controller, so it is a matter of knowing how to make the best use of the controls of this system (traffic lights) so as to make traffic more fluid. The values of the commands computed by the controller are determined by an algorithm which is ultimately, only solves a mathematical model representing the problem to be solved. The objective is to make a study and then the comparison on the optimization techniques based on artificial intelligence1 to intelligently route vehicle traffic. These techniques make it possible to minimize a certain function expressing the congestion of the road network. It can be a function, the length of the queue at intersections, the average waiting time, also the total number of vehicles waiting at the intersection


2018 ◽  
Vol 18 (2) ◽  
pp. 133
Author(s):  
Ni Luh Wayan Rita Kurniati

ABSTRACTTransportation problem is one of the problem that often encountered in large cities nowadays which one of the city is Pekanbaru. The main factor toward having good quality of transport infrastructure system is the performance of road, particularly the intersection performance as part of the whole road system. Congestion and long queues often occurred in Pekanbaru and mostly at intersections, ie at signalized intersections in the Arenka Market. Thus specific observations conducted on peak hours (peak hours) on the system of the traffic light. In order to measure the intersections performance, this study is using the manual method of Indonesian Highway Capacity, 1997 (MKJI-1997). The analysis method are using intersection capacity analysis, long queues analysis, phase system and delay. The results of the study showed that the performance evaluation existing at the intersection of Arenka Market with the arrangements of phase 4 and cycle time for 147 seconds, was at the range of between E and F. The calculation value of the saturation degree for Hr. Soebrantas street was 0.94 while for Soekarno Hatta street to the North was about 0.93. Based on Indonesian Highway Capacity Manual 1997, for the value of saturation degree (DS) > 0.85, means that the time signal including the road conditions must be reset.ABSTRAKMasalah transportasi merupakan salah satu masalah yang sering dihadapi di kota-kota besar salah satunya adalah Kota Pekanbaru saat ini. Salah satu faktor penting dalam usaha menuju sistem prasarana transportasi yang baik adalah kemampuan kinerja jalan, khususnya kinerja simpang sebagai salah satu bagian dari sistem jalan secara keseluruhan. Permasalahan kemacetan dan antrian yang panjang di Pekanbaru terjadi pada persimpangan, yaitu pada persimpangan bersinyal di Pasar Pagi Arenka Pengamatan khusus dilakukan pada jam-jam puncak (peak hour) pada sistem traffic light pada tersebut. Untuk mengukur kinerja persimpangan dalam penelitian ini menggunakan metode Manual Kapasitas Jalan Indonesia 1997 (MKJI-1997). Analisis yang dilakukan adalah analisis terhadap kapasitas persimpangan, panjang antrian, sistem fase serta tundaan. Data hasil analisis dari hasil evaluasi kinerja Simpang Pasar Pagi Arenka eksisting dengan pengaturan 4 fase dan waktu siklus 147 detik, didapat tingkat pelayanan simpang pasar pagi arenka berkisar dari E s/d F. Nilai perhitungan derajat kejenuhan untuk Jalan Hr. Soebrantas adalah 0,94 sedangkan Jalan Soekarno Hatta arah Utara sebesar 0,93. Menurut sumber Manual Kapasitas Jalan tahun 1997, untuk derajat kejenuhan (DS) > 0,85, maka jalan tersebut harus di atur ulang untuk waktu sinyal maupun kondisi jalannya.


Author(s):  
Andrzej P. Tarko ◽  
Zong Tian

Dealing with uncertainty is inevitable when the performance of transportation systems is estimated and predicted. Various sources of uncertainty and how uncertainty can be handled are demonstrated. An example single stream at an unsignalized intersection is considered as an illustration. The data collected in the field were used to present sources of uncertainty and their contribution to prediction error. Interval values are proposed to represent the prediction uncertainty. This approach is advantageous over rigorous statistical estimation when distributions of the variables and interactions between them are not well specified. Also addressed is drivers’ adjusting behavior to changing traffic performance. A simple volume elasticity approach is used to address traffic diversion and to provide realistic estimation of interval values of future delay. This study should be a useful introduction to the uncertainty issue in traffic analysis based on the Highway Capacity Manual.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2308 ◽  
Author(s):  
Can Bıyık

The smart city transport concept is viewed as a future vision aiming to undertake investigations on the urban planning process and to construct policy-pathways for achieving future targets. Therefore, this paper sets out three visions for the year 2035 which bring about a radical change in the level of green transport systems (often called walking, cycling, and public transport) in Turkish urban areas. A participatory visioning technique was structured according to a three-stage technique: (i) Extensive online comprehensive survey, in which potential transport measures were researched for their relevance in promoting smart transport systems in future Turkish urban areas; (ii) semi-structured interviews, where transport strategy suggestions were developed in the context of the possible imaginary urban areas and their associated contextual description of the imaginary urban areas for each vision; (iii) participatory workshops, where an innovative method was developed to explore various creative future choices and alternatives. Overall, this paper indicates that the content of the future smart transport visions was reasonable, but such visions need a considerable degree of consensus and radical approaches for tackling them. The findings offer invaluable insights to researchers inquiring about the smart transport field, and policy-makers considering applying those into practice in their local urban areas.


Author(s):  
Zihang Wei ◽  
Yunlong Zhang ◽  
Xiaoyu Guo ◽  
Xin Zhang

Through movement capacity is an essential factor used to reflect intersection performance, especially for signalized intersections, where a large proportion of vehicle demand is making through movements. Generally, left-turn spillback is considered a key contributor to affect through movement capacity, and blockage to the left-turn bay is known to decrease left-turn capacity. Previous studies have focused primarily on estimating the through movement capacity under a lagging protected only left-turn (lagging POLT) signal setting, as a left-turn spillback is more likely to happen under such a condition. However, previous studies contained assumptions (e.g., omit spillback), or were dedicated to one specific signal setting. Therefore, in this study, through movement capacity models based on probabilistic modeling of spillback and blockage scenarios are established under four different signal settings (i.e., leading protected only left-turn [leading POLT], lagging left-turn, protected plus permitted left-turn, and permitted plus protected left-turn). Through microscopic simulations, the proposed models are validated, and compared with existing capacity models and the one in the Highway Capacity Manual (HCM). The results of the comparisons demonstrate that the proposed models achieved significant advantages over all the other models and obtained high accuracies in all signal settings. Each proposed model for a given signal setting maintains consistent accuracy across various left-turn bay lengths. The proposed models of this study have the potential to serve as useful tools, for practicing transportation engineers, when determining the appropriate length of a left-turn bay with the consideration of spillback and blockage, and the adequate cycle length with a given bay length.


Author(s):  
Suhaib Al Shayeb ◽  
Nemanja Dobrota ◽  
Aleksandar Stevanovic ◽  
Nikola Mitrovic

Traffic simulation and optimization tools are classified, according to their practical applicability, into two main categories: theoretical and practical. The performance of the optimized signal timing derived by any tool is influenced by how calculations are executed in the particular tool. Highway Capacity Software (HCS) and Vistro implement the procedures defined in the Highway Capacity Manual, thus they are essentially utilized by traffic operations and design engineers. Considering its capability of timing diagram drafting and travel time collection studies, Tru-Traffic is more commonly used by practitioners. All these programs have different built-in objective function(s) to develop optimized signal plans for intersections. In this study, the performance of the optimal signal timing plans developed by HCS, Tru-Traffic, and Vistro are evaluated and compared by using the microsimulation software Vissim. A real-world urban arterial with 20 intersections and heavy traffic in Fort Lauderdale, Florida served as the testbed. To eliminate any bias in the comparisons, all experiments were performed under identical geometric and traffic conditions, coded in each tool. The evaluation of the optimized plans was conducted based on average delay, number of stops, performance index, travel time, and percentage of arrivals on green. Results indicated that although timings developed in HCS reduced delay, they drastically increased number of stops. Tru-Traffic signal timings, when only offsets are optimized, performed better than timings developed by all of the other tools. Finally, Vistro increased arrivals on green, but it also increased delay. Optimized signal plans were transferred manually from optimization tools to Vissim. Therefore, future research should find methods for automatically transferring optimized plans to Vissim.


2021 ◽  
pp. 001955612110016
Author(s):  
Anurima Mukherjee Basu ◽  
Rutool Sharma

Current urbanisation trends in India show a quantum jump in number of ‘census towns’, which are not statutorily declared as urban areas, but have acquired all characteristics of urban settlements. Sizeable number of such census towns are not located near any Class 1 city. Lack of proper and timely planning has led to unplanned growth of these settlements. This article is based on a review of planning legislations, institutional framework and planning process of four states in India. The present article analyses the scope and limitations of the planning process adopted in the rapidly urbanising rural areas of these states. The findings reveal that states are still following a conventional approach to planning that treats ‘urban’ and ‘rural’ as separate categories and highlights the need for adopting an integrated territorial approach to planning of settlements.


Author(s):  
Aidin Massahi ◽  
Mohammed Hadi ◽  
Maria Adriana Cutillo ◽  
Yan Xiao

The effect of incidents on capacity is the most critical parameter in estimating the influence of incidents on network performance. The Highway Capacity Manual 2010 (HCM 2010) provides estimates of the drop in capacity resulting from incidents as a function of the number of blocked lanes and the total number of lanes in the freeway section. However, there is limited information on the effects of incidents on the capacity of urban streets. This study investigated the effects on capacity of the interaction between the drop in capacity below demand at a midblock urban street segment location and upstream and downstream of signalized intersection operations. A model was developed to estimate the drop in capacity at the incident location as a function of the number of blocked lanes, the distance from the downstream intersection, and the green time–to–cycle length (g:C) ratio of the downstream signal. A second model was developed to estimate the reduction in the upstream intersection capacity resulting from the drop in capacity at the midblock incident location as estimated by the first model. The second model estimated the drop in capacity of the upstream links feeding the incident locations as a function of incident duration time, the volume-to-capacity (V/C) ratio at the incident location, and distance from an upstream signalized intersection. The models were developed on the basis of data generated with the use of a microscopic simulation model calibrated by comparison with parameters suggested in HCM 2010 for incident and no-incident conditions and by comparison with field measurements.


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