An integrated variable speed limit and ALINEA ramp metering model in the presence of High Bus Volume

Under many circumstances, when providing full bus priority methods, urban transport officials have to operate buses in mixed traffic based on their road network limitations. In the case of Istanbul’s Metrobus lane, for instance, when the route comes to the pre-designed Bosphorus Bridge, it has no choice but to merge with highway mixed traffic until it gets to the other side. Much has been written on the relative success of implementing Ramp Metering (RM), for example ALINEA (‘Asservissement line´ aire d’entre´ e autoroutie’) and Variable Speed Limits (VSL), two of the most widely-used “merging congestion” management strategies, in both a separate and combined manner. However, there has been no detailed study regarding the combination of these systems in the face of high bus volume. This being the case, the ultimate goal of this study is to bridge this gap by developing and proposing a combination of VSL and RM strategies in the presence of high bus volume (VSL+ALINEA/B). The proposed model has been coded using microscopic simulation software—VISSIM—and its vehicle actuated programming (VAP) feature; referred to as VisVAP. For current traffic conditions, the proposed model is able to improve total travel time by 9.0%, lower the number of average delays of mixed traffic and buses by 29.1% and 81.5% respectively, increase average speed by 12.7%, boost bottleneck throughout by 2.8%, and lower fuel consumption, Carbon Monoxide (CO), Nitrogen Oxides (NOx), and Volatile Organic Compounds (VOC) emissions by 17.3% compared to the existing “VSL+ALINEA” model. The results of the scenario analysis confirmed that the proposed model is not only able to decrease delay times on the Metrobus system but is also able to improve the adverse effects of high bus volume when subject to adjacent mixed traffic flow along highway sections

Exploring equity in public transportation planning using smart card data

Existing public transport (PT) planning methods use a trip-based approach, rather than a user-based approach, leading to neglecting equity. In other words, the impacts of regular users—i.e., users with higher trip rates—are overrepresented during analysis and modelling because of higher trip rates. In contrast to the existing studies, this study aims to show the actual demand characteristic and users’ share are different in daily and monthly data. For this, 1-month of smart card data from the Kocaeli, Turkey, was evaluated by means of specific variables, such as boarding frequency, cardholder types, and the number of users, as well as a breakdown of the number of days traveled by each user set. Results show that the proportion of regular PT users to total users in 1 workday, is higher than the monthly proportion of regular PT users to total users. Accordingly, users who have 16–21 days boarding frequency are 16% of the total users, and yet they have been overrepresented by 39% in the 1-day analysis. Moreover, users who have 1–6 days boarding frequency, have a share of 66% in the 1-month dataset and are underrepresented with a share of 22% in the 1-day analysis. Results indicated that the daily travel data without information related to the day-to-day frequency of trips and PT use caused incorrect estimation of real PT demand. Moreover, user-based analyzing approach over a month prepares the more realistic basis for transportation planning, design, and prioritization of transport investments

An automatic calibration procedure of driving behaviour parameters in the presence of high bus volume

Most of the microscopic traffic simulation programs used today incorporate car-following and lane-change models to simulate driving behaviour across a given area. The main goal of this study has been to develop an automatic calibration process for the parameters of driving behaviour models using metaheuristic algorithms. Genetic Algorithm (GA), Particle Swarm Optimization (PSO), and a combination of GA and PSO (i.e. hybrid GAPSO and hybrid PSOGA) were used during the optimization stage. In order to verify our proposed methodology, a suitable study area with high bus volume on-ramp from the 0-1 Highway in Istanbul has been modelled in VISSIM. Traffic data have been gathered through detectors. The calibration procedure has been coded using MATLAB and implemented via the VISSIM-MATLAB COM interface. Using the proposed methodology, the results of the calibrated model showed that hybrid GAPSO and hybrid PSOGA techniques outperformed the GA-only and PSO-only techniques during the calibration process. Thus, both are recommended for use in the calibration of microsimulation traffic models, rather than GA-only and PSO-only techniques.This study is a part of Ph.D. thesis of the corresponding author from the Istanbul Technical University, Turkey. We would like to thank Prof. Dr. Toma? Maher and Assist. Dr. Rok Marseti? from the Traffic Technical Institute of Civil and Geodetic Engineering Faculty, University of Ljubljana, Slovenia, for their kind support, valuable comments, and helpful suggestions. The authors are also thankful to the PTV-AG Karlsruhe Company for their support in providing a thesis-based unlimited version of VISSIM softwarePublisher's Versio

Mobility as a service Inclusion Index (MaaSINI): Evaluation of inclusivity in MaaS systems and policy recommendations

According to UN statistics, the population of people in vulnerable social groups, namely elderly people, people with disabilities, and low-income populations, has increased over the recent decades. It is projected that this trend will continue in the future. Thus, their mobility and access to transport services are important areas to study. Mobility as a Service (MaaS) is a digital platform (smartphone application) that aims to encourage more sustainable travel. MaaS is promoted as being accessible to all user groups. However, there are limited studies linking MaaS with vulnerable social groups and their particular needs. This paper comprehensively reviews studies on the emergence of such platforms since 2014 until today to identify the research gaps with respect to vulnerable social groups. A framework and MaaS Inclusion Index (MaaSINI) are then proposed to evaluate the inclusion in MaaS services, focusing on vulnerable social groups’ needs at a service level instead of a city/area level. The framework and policy recommendations proposed in this study will make a significant contribution in guiding stakeholders and policymakers in implementing accessible-for-all-users MaaS services targeting sustainable and inclusive transport

An Automatic Calibration Procedure of Driving Behaviour Parameters in the Presence of High Bus Volume

Most of the microscopic traffic simulation programs used today incorporate car-following and lane-change models to simulate driving behaviour across a given area. The main goal of this study has been to develop an automatic calibration process for the parameters of driving behaviour models using metaheuristic algorithms. Genetic Algorithm (GA), Particle Swarm Optimization (PSO), and a combination of GA and PSO (i.e. hybrid GAPSO and hybrid PSOGA) were used during the optimization stage. In order to verify our proposed methodology, a suitable study area with high bus volume on-ramp from the O-1 Highway in Istanbul has been modelled in VISSIM. Traffic data have been gathered through detectors. The calibration procedure has been coded using MATLAB and implemented via the VISSIM-MATLAB COM interface. Using the proposed methodology, the results of the calibrated model showed that hybrid GAPSO and hybrid PSOGA techniques outperformed the GA-only and PSO-only techniques during the calibration process. Thus, both are recommended for use in the calibration of microsimulation traffic models, rather than GA-only and PSO-only techniques.</p

Who is willing to share their AV? Insights about gender differences among seven countries

The introduction of shared autonomous vehicles into the transport system is suggested to bring significant impacts on traffic conditions, road safety and emissions, as well as overall reshaping travel behaviour. Compared with a private autonomous vehicle, a shared automated vehicle (SAV) is associated with different willingness-to-adopt and willingness-to-pay characteristics. An important aspect of future SAV adoption is the presence of other passengers in the SAV—often people unknown to the cotravellers. This study presents a cross-country exploration of user preferences and WTP calculations regarding mode choice between a private non-autonomous vehicle, and private and shared autonomous vehicles. To explore user preferences, the study launched a survey in seven European countries, including a stated-preference experiment of user choices. To model and quantify the effect of travel mode attributes and socio-demographic characteristics, the study employs a mixed logit model. The model results were the basis for calculating willingness-to-pay values for all countries and travel modes, and provide insight into the significant heterogeneous, gender-wise effect of cotravellers in the choice to use an SAV. The study results highlight the importance of analysis of the effect of SAV attributes and shared-ride conditions on the future acceptance and adoption rates of such services

Karma trafik akışında otobüs önceliği yöntemlerinin etkileri

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2019Theses (Ph.D.) -- İstanbul Technical University, Institute of Science and Technology, 2019Günümüzde, araç doluluk oranının düşük olduğu otomobile bağımlı şehirler, gecikmelere yol açan yoğun trafik sıkışıklığı ile karşı karşıya kalmaktadır. Ulaşım kapasitesini arttırmak ve aynı zamanda trafik sıkışıklığını azaltmak amacıyla sürdürülebilir çözüm, örneğin otobüs gibi etkili toplu taşıma araçlarının uygulamasıdır. Ayrıca, otobüslerin kullanım kapasitesini artırmak için dunya çapinda toplu taşıma önceliği yöntemleri, örnekle otobüs şeridi uygulaması popüler hale gelmiştir. Bu çalışma, otobüs önceliği yöntemleri, uygulama zorlukları ve ihtiyaçları ile ilgili çalışmalara kapsamlı bir genel bakış sunmaktadır. Çalışmada; elde edilen sonuçlar önceki çalışmaların bulgularıyla birleştirilerek, etkili bir otobüs şeridi uygulaması için kapsamlı bir kılavuz formüle edilebilmiştir. Bu calismada önerilen kılavuz; karar vericilerin, planlamacıların, mühendislerin ve operatörlerin yerel bağlamda başarılı bir BL elde etmelerini sağlayacaktır. Öte yandan, bazı durumlarda şehir içi ulaşım görevlileri, tam otobüs önceliği yöntemlerinin sağlanmasındaki yol ağı sınırlamalarına dayanarak karma trafikte otobüs işletmek zorundadır. Örneğin, İstanbul Metrobüsü Boğaziçi Köprüsününden geçmek için, E5 karayolundaki karma trafiğe katilmak zorundadir (YILDIZ rampasi veya birleşme alanı olarak bilinir). Bu birleşme alanı, karma trafikte bu denli yüksek oranlı otobüs hacimlerinin operasyon etkilerdi de göz önüne alındığında, seçilebilecek en iyi çalışma yeri olabilir. Bu nedenle, YILDIZ birleşme alanı, bu olayın etkilerini analiz etmek amacıyla, mikroskobik trafik simülasyon yazılımı VISSIM'de modellenmiştir. Hız, hacim ve doluluk dahil olmak üzere trafik verileri, bölgede bulunan dedektörler aracılığıyla toplanmıştır. Günümüzde kullanılan mikroskobik trafik simülasyon programlarının çoğu, belirli bir alandaki sürüş davranışını simüle etmek için araç takip ve şerit değiştirme modellerini içermektedir. Bu nedenle, tezin birinci amacı; İstanbul için iyi ayarlanmış sürüş davranışı parametrelerini belirlemek icin, metaheuristik algoritmalar kullanarak trafik simülasyonu modellerinin otomatik kalibrasyon prosedürünü geliştirmektir. Genetik Algoritma'nın (GA) yerel arama kabiliyeti ve Parçacık Sürü Optimizasyonunun (PSO) bilgi alışverişi kabiliyeti kullanılarak, bu algoritmaların sınırlamalarını aşmak için yeni bir GA ve PSO kombinasyonu (yani, hibrit GAPSO ve hibrit PSOGA) geliştirilmıştır. Kalibrasyon prosedürü MATLAB programin kullanılarak kodlanmış ve VISSIM-MATLAB COM arayüzü ile YILDIZ modeli uzerinde uygulanmıştır. Kalibre edilmiş modelin sonuçları, hibrit GAPSO ve hibrit PSOGA tekniklerinin yalnızca GA ve PSO tekniklerinde daha iyi performans gösterdiğini ve her iki amaç fonksyonu icin (yani hem MANE hem de RMSE) en düşük değerinin hibrit GAPSO algoritması ile elde edildiğini göstermiştir. Bu nedenle, her ikisinin de, yalnızca GA ve yalnızca PSO teknikleri yerine, mikrosimülasyon trafik modellerinin kalibrasyonunda kullanılması önerilmektedir. Ama, trafik simülasyon modelleri için kalibrasyon prosedürü, büyük ölçekli ve karmaşık bir ağ söz konusu olduğunda çok zaman alan bir işlem olabilir. Bu çalışmanın bir başka katkısı, EA ve paralel hesaplama tekniklerini (PHT'ler) kullanarak hızlı bir kalibrasyon prosedürü geliştirmektir. Bu amaçla, PHT olan/olmayan iki kalibrasyon senaryosu analiz edildi. PHT'nin önerilen hibrit modellerde uygulanmasının, optimizasyon sürecinin toplam hesaplama süresini önemli ölçüde (deneylerimizde %45-65 kadar) azaltabildiği bulundu. VISSIM'in vaka çalışması alanı için en iyi eşlenen sürüş davranış parametreleri, önerilen kalibrasyon prosedürü ile elde edildikten sonra, yüksek otobüs hacminin varlığında yeni katılım kontrol yöntemleri geliştirilebilir. Katılım kontrolü (KK) örn. ALINEA ve değişken hız sınırı (DHS), özellikle otoyollardaki birleşim tıkanıklıkları için yaygın olarak kullanılan ve etkili sıkışıklık yönetimi stratejileridir. Yapılan literatür taramasına göre, KK ve DHS stratejilerinin ayrı ve kombine bir şekilde uygulanması üzerine bir çok çalışma yapılmıştır. Ancak, yüksek otobüs hacmi sorunu göz önüne alındığında bu sistemlerin kombinasyonuyla ilgili ayrıntılı bir çalışma yoktur. Yüksek otobüs hacmi, özellikle şehir içi otoyolların birleşme noktalarındaki sürüş davranışını (örneğin şerit değiştirme) doğrudan etkiliyor olup, bu da otoyol alanlarında kapasite düşüşüne neden olmaktadır. YILDIZ rampasına Transit Sinyali Önceliğinin (TSÖ) kurulması, otobüslerin rampa üstü araçlarla etkileşimini azaltmak ve aynı zamanda otobüs gecikmelerini ortadan kaldırmak için basit bir çözüm olabilir. Ama, bir yandan, otobüslere hareket önceliği vermek zorunda olan rampa üzerindeki araç gecikmelerini doğrudan etkileyecek olup, diğer yandan otobüslerin karayolunun karma trafiği ile etkileşimlerini kontrol edemeyecektir. Ana yol (otoyol), rampa ve otobüsler gibi üç tür akış arasında çeşitli çakışmaların olduğu bu kadar karmaşık bir durumda, tüm etkileşimleri kontrol edebilen entegre bir modele sahip olmak gerekir. Bu sebeple, son olarak bu çalışmanın nihai amaçı, yüksek otobüs hacminin varlığında (örnegin E5 otoyoluna giren Metrobüs aracları), birleştirilmiş DHS ve KK stratejileri geliştirerek ve önererek literatürdeki boşluğu ele almaktır. Yüksek otobüs hacmini dikkate alan entegre DHS ve ALINEA modeli (DHS+ALINEA/O olarak adlandırılmış) VisVAP ile kodlanmış ve kalibre edilmiş modele uygulanmıştır. Kalibre edilmiş YILDIZ birleşim simülasyon modelinde i) kontrolsüz, ii) kontrollü (TSÖ, ALINEA, DHS, DHS+ALINEA, DHS+ALINEA/O) çeşitli senaryolar test edilmiştir. Önerilen DHS+ALINEA/O modeli kombine DHS+ALINEA gibi mevcut modelle karşılaştırdığında, toplam yolculuk süresini % 6.6 oranında, ortalama hızı % 7.4 oranında, darboğazdan geçiş kapasitesini ortalama % 2.5 oranında, yakıt tüketimini, CO, NOx, ve VOC emisyonlarını ortalama %8.4 oranında iyileştirebilir ve hatta diğer mevcut senariolara gore örn. kontrolsüz, TSÖ, DHS, KK daha iyi performans göstermektedir. Son olarak, önerilen DHS+ALINEA/O model performansı, farklı olası koşullarda etkinliğini analiz etmek için farklı otobüs hacimleriyle test edilmiştir. Senaryo analizinin sonuçları göstermiştir ki, önerilen DHS+ALINEA/O modeli, yalnızca otobüs gecikmesini azaltmakla kalmaz, aynı zamanda yüksek otobüs hacimlerinin karayollarının ana hatlarındaki karma trafik hareketleri üzerindeki olumsuz etkilerini de iyileştirir.Nowadays, car-dependent cities with low car occupancy are facing heavy traffic congestion, resulting in delays. A sustainable solution with the aim to simultaneously increase transport capacity and decrease traffic jams is the implementation of effective public transport, e.g. buses. Globally, bus priority methods, e.g. bus lane (BL), have become popular strategies to increase the utilization of bus transport's capacity. This thesis gives a comprehensive overview of prior studies related to bus priority methods and their implementation challenges and needs together with clustering the most influencing factors in the implementation and operation of BLs. Under some circumstances, urban transport officials have to operate buses in the mixed traffic based on their road network limitations in providing full bus priority methods. For instance, Istanbul's Metrobus (a segregated BL) has to merge to O-1 highway mixed traffic (known as YILDIZ merging area) to cross the Bosphorus bridge. This is selected as the best-case study for examining the operational effects of a high rate bus volume in mixed traffic. In order to analyses the effects of this phenomena, YILDIZ merging area is modelled in microscopic traffic simulation software, VISSIM, Traffic data such as speed, volume, and occupancy are gathered through detectors installed in the area. As most of the microscopic traffic simulation programs used today incorporate car-following and lane-change models to simulate driving behavior across a given area, the first objective of the thesis is to develop an automatic calibration procedure of traffic simulations models using metaheuristic algorithms, in order to find well-tuned driving behavior parameters in the presence of high rate bus volume for the real conditions of Istanbul. Local search capability of Genetic Algorithm (GA) and swarm's information exchange ability of Particle Swarm Optimization (PSO) are used in order to develop a new combination of the GA and PSO (i.e. hybrid GAPSO and hybrid PSOGA) to overcome the limitations of those algorithms. The calibration procedure is coded using MATLAB and implemented via the VISSIM-MATLAB COM interface on YILDIZ model. The result of the calibrated model shows that hybrid GAPSO and hybrid PSOGA techniques outperformed the GA-only and PSO-only techniques, and that the lowest value of objective functions (i.e. MANE and RMSE) are achieved with the hybrid GAPSO algorithm. Thus, both are recommended for use in the calibration of microsimulation traffic models, rather than GA-only and PSO-only techniques. However, the calibration procedure for traffic simulation models can be a time-consuming process in the case of large-scale and complex networks. Another contribution of this study is to develop a quick calibration procedure using EA and parallel computing techniques (PCTs). To this end, two calibration scenarios with/without PCT have been analyzed. It is found that the implementation of PCT on proposed hybrid models can significantly reduce the total computational time of the optimization process - in these experiments by 45-65%. Once the best-matched sets of VISSIM's driving behavior parameters for the case study area is obtained through the proposed calibration procedure, it is necessary to develop new ramp control methods in the presence of a high volume of buses. Ramp metering (RM) e.g. ALINEA and variable speed limit (VSL) are two widely used and effective congestion management strategies, especially for "merging congestion" on highways. According to the literature review conducted, the implementation of RM and VSL strategies in a separate and combined manner have been thoroughly studied. However, there is no detailed study regarding the combination of these systems in relation to issues with high bus volume. High bus volume directly affects driving behavior (e.g. lane changing) especially in merging points of urban highways, causing a decrease in the capacity of these areas of highways. Installation of Transit Signal Priority (TSP) on the YILDIZ ramp can be a simple solution to decrease the interaction of buses with on-ramp vehicles as well as buses delays reduction. It will directly affect on-ramp vehicle delays, which have to give movement priority to buses, however, it cannot control the interaction of buses with highway mixed traffic. Such a complex condition necessitates an integrated model which is able to control all interactions and avoid conflicts among three types of traffic flow - namely mainline (highway), on-ramp, and buses. Therefore, the ultimate goal of this study is to address the gap in the literature by developing and proposing a combined VSL and RM strategies in presence of high bus volume (e.g. Metrobus vehicles in YILDIZ merging segment). Integrated VSL and ALINEA model considering high bus volume (called VSL+ALINEA/B) have been coded and applied to the calibrated model through the VisVAP. Various scenarios with i) no control, and ii) with control (TSP, ALINEA, VSL, VSL+ALINEA/B) have been tested on the calibrated YILDIZ merging simulation model. For current traffic conditions, proposed VSL+ALINEA/B is able to improve total travel time by 6.6%, average delays of mixed traffic and buses by 28.1% and 48.5% respectively, average speed by 7.4%, bottleneck throughout (capacity) by 2.5%, and fuel consumption, CO, NOx, VOC emissions by 8.4% on average when compared to an existing "VSL+ALINEA" model. The simulation performs even better when compared to other models such as No Control, VSL, ALINEA, and TSP. Lastly, the proposed VSL+ALINEA/B model performance has been tested with different bus volumes, in order to analyze its effectiveness in different traffic conditions. Results of the scenario analysis confirmed that the proposed VSL+ALINEA/B model is not only able to decrease the delays of buses, but can also improve the adverse effects of high bus volume on mixed traffic flow in highways.DoktoraPh.D

Spatial bus priority schemes, implementation challenges and needs: an overview and directions for future studies

Urban transit systems consist of multiple modes of transport of which cars and buses make up the largest portion, particularly in developing countries. Thus, theories on the best means of allocating existing road spaces for cars and buses in city-centers and suburban corridors in order to improve operational transport efficiency has become a frontier research topic. Today, bus priority (BP) methods, as one of the most widely used Public Transport Priority (PTP) strategies, are commonly recognized as effective in lowering traffic congestion and reducing bus travel times. PT authorities, urban planners/designers, and researchers dealing with PT issues (i.e. buses), need to investigate existing BP methods in detail and assess relevant research before setting about designing or implementing new policies. Of course, evaluating such studies is a time-consuming process. In order to address this constraint, the present study proposes a general typology of existing BP methods and evaluates the challenges and requirements regarding their implementation by conducting a comprehensive literature review of existing studies related to PTP. Academic papers (theoretical, analytical, and simulation-based), technical reports, and design manual/guidelines in the context of both developed and developing countries have been searched as part of the literature review process. The study concludes by proposing two comparative summary tables of all spatial bus priority schemes in terms of “min. requirements to justify BP schemes” and “advantages and disadvantages of time-based and spatial BP treatments”. These may provide engineers, urban planners or transit policy-makers with an accessible guide with which to refer in the evaluation stage. However, future research is recommended in order to bridge existing gaps concerning conditions required for the successful implementation of spatial bus priority strategies

An integrated variable speed limit and ALINEA ramp metering model in the presence of high bus volume

Under many circumstances, when providing full bus priority methods, urban transport officials have to operate buses in mixed traffic based on their road network limitations. In the case of Istanbul\u27s Metrobus lane, for instance, when the route comes to the pre-designed Bosphorus Bridge, it has no choice but to merge with highway mixed traffic until it gets to the other side. Much has been written on the relative success of implementing Ramp Metering (RM), for example ALINEA (Asservissement linéaire d’entrée autoroutière) and Variable Speed Limits (VSL), two of the most widely-used “merging congestion” management strategies, in both a separate and combined manner. However, there has been no detailed study regarding the combination of these systems in the face of high bus volume. This being the case, the ultimate goal of this study is to bridge this gap by developing and proposing a combination of VSL and RM strategies in the presence of high bus volume (VSL+ALINEA/B). The proposed model has been coded using microscopic simulation software—VISSIM—and its vehicle actuated programming (VAP) featurereferred to as VisVAP. For current traffic conditions, the proposed model is able to improve total travel time by 9.0%, lower the number of average delays of mixed traffic and buses by 29.1% and 81.5% respectively, increase average speed by 12.7%, boost bottleneck throughout by 2.8%, and lower fuel consumption, Carbon Monoxide (CO), Nitrogen Oxides (NOx), and Volatile Organic Compounds (VOC) emissions by 17.3% compared to the existing “VSL+ALINEA” model. The results of the scenario analysis confirmed that the proposed model is not only able to decrease delay times on the Metrobus system but is also able to improve the adverse effects of high bus volume when subject to adjacent mixed traffic flow along highway sections