Developing and Field Testing a Green Light Optimal Speed Advisory System for Buses

This paper develops a Green Light Optimal Speed Advisory (GLOSA) system for buses (B-GLOSA). The proposed B-GLOSA system is implemented on diesel buses, and field tested to validate and quantify the potential real-world benefits. The developed system includes a simple and easy to calibrate fuel consumption model that computes instantaneous diesel bus fuel consumption rates. The bus fuel consumption model, a vehicle dynamics model, the traffic signal timings, and the re-lationship between vehicle speed and distance to the intersection are used to construct an optimi-zation problem. A moving-horizon dynamic programming problem solved using the A-star algo-rithm is used to compute the energy-optimized vehicle trajectory through signalized intersections. The Virginia Smart Road test facility was used to conduct the field test on 30 participants. Each participant drove three scenarios including a base case uninformed drive, an informed drive with signal timing information communicated to the driver, and an informed drive with the recom-mended speed computed by the B-GLOSA system. The field test investigated the performance of using the developed B-GLOSA system considering different impact factors, including road grades and red indication offsets, using a split-split-plot experimental design. The test results demonstrated that the proposed B-GLOSA system can produce smoother bus trajectories through signalized in-tersections producing fuel consumption and travel time savings. Specifically, compared to the uninformed drive, the B-GLOSA system produces fuel and travel time savings of 22.1% and 6.1% on average, respectively.

Quantifying the Impact of the COVID-19 Pandemic on Passenger Vehicle Drivers’ Willingness to Pay for Travel Time Savings and Reliability

The COVID-19 pandemic has fundamentally disrupted travel behavior and consumer preferences. To slow the spread of the virus, public health officials and state and local governments issued stay-at-home orders and, among other actions, closed nonessential businesses and educational facilities. The resulting recessionary effects have been particularly acute for U.S. toll roads, with an observed year-over-year decline in traffic and revenue of 50% to 90% in April and May 2020. These disruptions have also led to changes in the types of trip that travelers make and their frequency, their choice of travel mode, and their willingness to pay tolls for travel time savings and travel time reliability. This paper describes the results of travel behavior research conducted on behalf of the Virginia Department of Transportation before and during the COVID-19 pandemic in the National Capital Region of Washington, D.C., Maryland, and Northern Virginia. The research included a stated preference survey to estimate travelers’ willingness to pay for travel time savings and travel time reliability, to support forecasts of traffic and revenue for existing and proposed toll corridors. The survey collected data between December 2019 and June 2020. A comparison of the data collected before and during the pandemic shows widespread changes in travel behavior and a reduction in willingness to pay for travel time savings and travel time reliability across all traveler types, particularly for drivers making trips to or from work. These findings have significant implications for the return of travelers to toll corridors in the region and future forecasts of traffic and revenue.

The role of unpaid domestic work in explaining the gender gap in the (monetary) value of leisure

The value of travel time savings (VTTS) representing the willingness to pay to reduce travel time, consists of two components: the value of liberating time [equal to the value of leisure (VoL)] and the value of time assigned to travel (VTAT), representing the travel conditions of a trip. Their relative values indicate which dimension to emphasize when investing in transport: speed or comfort. In this paper, we formulate and estimate a framework aimed at the improvement in the estimation of the VoL. By introducing a novel treatment of time assigned to domestic work, we consider that unpaid labor should be assigned a wage rate as a measure of the expenses avoided when assigning time to those chores. We use state-of-the-art data on time use and expenses as well as online data on gig workers collected in Austria, and apply the time-use and expenditure model of Jara-Diaz et al. (Transp Res Part B 42(10):946–957, 2008). The wage rates for paid and unpaid work were combined to re-formulate the budget constraint, which affected women more than men due to the higher involvement of the former in domestic activities. Compared against the original estimation, the VoL changed from €10/h for men and €6/h for women to €9/h for both genders, which in turn yields a larger average VTAT, which becomes positive for public transport. As a conclusion, the novel treatment of domestic labor contributes to closing the gap in the VoL between genders and highlights the power of unveiling the components behind the VTTS. The empirical findings imply that investments in travel time reductions rather than in comfort should be prioritized, given the very good conditions of public transport in Austria.

Assessing road pricing effects on a multimodal network based on macroscopic fundamental diagram hysteresis

Purpose Road pricing is an efficient strategy for managing urban traffic to relieve congestion. The macroscopic fundamental diagram (MFD), which relates the average network density and flow, is a simple tool for assessing road pricing effects on transportation network performance. However, recent research indicates that it may have complexity (an MFD hysteresis loop), especially for city-scale networks. Although ignoring MFD hysteresis may provide inaccurate results, pricing models that consider this hysteresis are scarce. This paper aims to assess road pricing effects on network performance considering MFD hysteresis characteristics. Design/methodology/approach This paper evaluated different pricing strategies spatially and temporally and compared network performance based on MFD shape in the presence of MFD hysteresis loops. These strategies were developed on a multimodal (cars and buses) network using a multi-agent transport simulation (MATSim). Findings This study found that pricing some links for a short duration with an optimum charge calculated based on the MFD provides higher travel time savings than the previous relevant studies. Originality/value These findings may facilitate assessing road pricing effects on multimodal network performance considering MFD hysteresis.

Ramp Metering with Microscopic Gap Detection Algorithm Design and Empirical Acceleration Verification

Freeway on-ramp areas are susceptible to traffic congestion during peak hours. To delay or prevent the onset of congestion, ramp metering can be applied. A Ramp Metering Installation (RMI) controls the inflow from the on-ramp to the main line so that the total flow can be kept just below capacity. Current ramp metering algorithms apply macroscopic traffic characteristics, which do not entirely prevent inefficient merging behavior from occurring. This paper presents a microscopic ramp metering approach based on gap detection in the right-hand lane of the main line. As preparation for the analyses, trajectory data were collected, by which the mean and standard deviation of driver accelerations were calculated. Simulation, including driver acceleration, is used to test the ramp metering controller. Overall, it shows travel-time savings compared with no-control and compared with existing macroscopic ramp metering systems. Especially during periods of very high main line demand, the microscopic control approach is able to achieve additional travel-time savings. This way, the proposed algorithm can contribute to more efficient road usage and shorter travel times.

The Commuting Mode Choice of Students of Institut Teknologi Bandung, Indonesia

This research explored the commuting mode preferences of students living near Institut Teknologi Bandung when a new mode of transportation (i.e., carpool) is introduced to the selection list. Six alternative modes were presented: minibus, car, motorcycle, car-based ride-sourcing, motorcycle-based ride-sourcing, and carpool. The data collection process was conducted using a questionnaire-based stated-preferences survey. It included eight sets of labeled scenarios with a number of attributes: travel time, travel cost, waiting time, transfer amount, access and egress time, frequency, congestion time, baggage cost, and parking cost. A total of 1416 observations were acquired for further analysis. A mixed logit (MXL) model with random cost parameter and random error components was used. From the MXL results, we found that travel cost had no significant influence on the selection of commuting mode among students. This result was unforeseen given the characteristics of Indonesian consumers, who are notoriously sensitive to price. However, based on the results for several significant attributes of carpool as well as from the value of travel time savings and demand calculation, we suggest that carpooling is a valid alternative transport mode for campus commuting. As a pioneer study on student commuting mode selection, this study provided valid and dependable evidence on how students around ITB main campus choose their transportation methods. Abstrak. Penelitian ini mengeksplorasi preferensi moda perjalanan pulang pergi mahasiswa yang tinggal di dekat Institut Teknologi Bandung ketika moda transportasi baru (yaitu angkutan bersama) menjadi salah satu pilihan moda. Terdata enam moda alternatif yang disajikan: angkot, mobil, sepeda motor, taksi daring, ojek daring, dan angkutan bersama. Proses pengumpulan data dilakukan dengan menggunakan metoda survei stated-preference berbasis kuesioner. Survei tersebut meliputi delapan skenario berlabel dengan sejumlah atribut: waktu perjalanan, biaya perjalanan, waktu tunggu, banyaknya perpindahan moda, waktu perjalanan menuju tempat angkutan umum dan waktu perjalanan menuju tempat tujuan, frekuensi kedatangan, waktu kemacetan, biaya bagasi, dan biaya parkir. Sebanyak 1416 pengamatan diperoleh untuk analisis lebih lanjut. Model mixed logit (MXL) dengan parameter biaya acak dan komponen error acak digunakan. Dari hasil MXL, kami menemukan bahwa biaya perjalanan tidak berpengaruh signifikan terhadap pemilihan moda perjalanan pulang pergi di kalangan mahasiswa. Hasil ini tidak terduga mengingat karakteristik konsumen Indonesia yang terkenal sensitif terhadap harga. Namun, berdasarkan hasil untuk beberapa atribut signifikan dari angkutan bersama serta dari nilai penghematan waktu perjalanan dan perhitungan permintaan, kami menyarankan bahwa angkutan bersama adalah moda transportasi alternatif yang valid untuk komuter kampus. Sebagai studi perintis dalam pemilihan moda perjalanan pulang pergi mahasiswa, studi ini memberikan bukti yang valid dan dapat diandalkan tentang bagaimana mahasiswa di sekitar kampus utama ITB memilih metode transportasi mereka. Keywords. angkutan bersama, mahasiswa ITB, mixed logit, elastisitas, nilai waktu.

The value of travel time savings in freight transport: a meta-analysis

The value of freight travel time savings (VFTTS) is a monetary value that is considered an important input into cost–benefit analysis and traffic forecasting. The VFTTS is defined as the marginal rate of substitution between travel time and cost and may therefore differ across firms, time and countries. The paper aims to explain variations in the VFTTS by using the meta-analysis method. The analysis covers 106 monetary valuations extracted from 56 studies conducted from 1988 to 2018 in countries across the globe. The meta-analysis method determines the factors that have an impact on these VFTTS variations. The paper briefly introduces the VFTTS concept and describes the adopted meta-analysis methodology, wherein different meta-models are used in VFTTS estimations. The results highlight the necessity of including multiple explanatory variables to ensure adequate explanation of the VFTTS variations. The findings also show that GDP per capita, transport mode and type of survey respondent are statistically significant variables. The paper sheds some light on the variations, thereby advancing the understanding of each factor’s effects on the VFTTS. Furthermore, meta-model outcomes are used to generate new values of travel time savings for different transport modes in freight transport, for several countries. These implied VFTTS can be used as benchmarks to assess existing evidence or provide new evidence to countries where no such values exist.

North Toronto rapid transit line feasibility study

Traffic congestion is an existing problem in North Toronto with Highway 401 and other area roads operating at capacity during peak hours. Future population and employment growth across north Toronto will increase traffic demands in the area. With many roads already operating at capacity, alternative non-auto modes of transportation will be required to accommodate future traffic demands and minimize future traffic congestion. Public transit is the best means of providing a non-auto transportation mode in north Toronto. Higher-order rapid transit can offer travel-time savings and many other benefits over auto-travel in congested conditions; however, no rapid transit service presently exists across north Toronto. This paper provides the rationale for a north Toronto rapid transit line and confirms its feasibility for its implementation.