Potential Single-Occupancy Vehicle Demand for High-Occupancy Vehicle Lanes

Author(s):  
Mark W. Burris ◽  
Lei Xu
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.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4349
Author(s):  
Niklas Wulff ◽  
Fabia Miorelli ◽  
Hans Christian Gils ◽  
Patrick Jochem

As electric vehicle fleets grow, rising electric loads necessitate energy systems models to incorporate their respective demand and potential flexibility. Recently, a small number of tools for electric vehicle demand and flexibility modeling have been released under open source licenses. These usually sample discrete trips based on aggregate mobility statistics. However, the full range of variables of travel surveys cannot be accessed in this way and sub-national mobility patterns cannot be modeled. Therefore, a tool is proposed to estimate future electric vehicle fleet charging flexibility while being able to directly access detailed survey results. The framework is applied in a case study involving two recent German national travel surveys (from the years 2008 and 2017) to exemplify the implications of different mobility patterns of motorized individual vehicles on load shifting potential of electric vehicle fleets. The results show that different mobility patterns, have a significant impact on the resulting load flexibilites. Most obviously, an increased daily mileage results in higher electricty demand. A reduced number of trips per day, on the other hand, leads to correspondingly higher grid connectivity of the vehicle fleet. VencoPy is an open source, well-documented and maintained tool, capable of assessing electric vehicle fleet scenarios based on national travel surveys. To scrutinize the tool, a validation of the simulated charging by empirically observed electric vehicle fleet charging is advised.


2013 ◽  
Vol 415 ◽  
pp. 582-585
Author(s):  
Xing Xu ◽  
Zhen Cui ◽  
Jin Chao Zhang

According to the indicator diagram of damper, the indicator diagram plumpness was proposed as a quantitative index, and its mathematical relationships with the sprung mass acceleration, suspension dynamic travel and tire dynamic load were built. Moreover, the influence of the total area on suspension characteristics was analyzed in time domain and frequency domain. The results show that, the increase of the indicator diagram plumpness can effectively restrain the variation of suspension dynamic travel and tire dynamic load, meanwhile, the body acceleration will be enlarged. Excessive indicator diagram plumpness also affects the dynamic tire load distribution in frequency domain, and it will decrease the driving security. Therefore, it should be reasonably selected from the performance indicators, which is based on the requirement of vehicle demand in the design process.


Author(s):  
Robert A. Johnston ◽  
Shengyi Gao ◽  
Michael J. Clay

The Sacramento, California, region has been engaged in an innovative long-range visioning process in 2004 and 2005; the regional transportation planning agency is defining and modeling several 50-year growth scenarios. The authors worked with environmental and social equity citizens’ groups to define policies that would reduce emissions, serve lower-income travelers better, and preserve habitats and agricultural lands in the region. The citizens’ groups rejected the new freeways planned for the region as well as the substantial freeway widenings for high-occupancy vehicle lanes. In addition, they defined a more ambitious transit system, involving new bus rapid transit lines and shorter headways for all rail and bus service. This transit-only plan was modeled by itself and along with a land use policy for an urban growth boundary and a pricing policy for higher fuel taxes and parking charges for work trips. A new version of the MEPLAN model was used to simulate these scenarios over 50 years, and findings about total travel, mode shares, congestion, emissions, land use changes, and economic welfare of travelers are described.


Author(s):  
John Parker ◽  
Christopher Poston ◽  
Richard Roser ◽  
Joel Anstrom ◽  
Timothy Cleary ◽  
...  

This technical paper provides instruction by example on how to apply hardware-in-the-loop (HIL) simulation for accelerated development of a complex control algorithm. The instruction provided in this technical paper is directed to HIL test bench setup, software, simulated and real hardware, and test methods. As an example, the authors reference their collaborative development project of the last couple of years, now completed. The objective of that project was to develop a demand-driven hydrogen production system and integrate it with a hydrogen-fueled internal combustion engine-powered vehicle test platform. The instruction provided in this technical paper is supported by data from the referenced project example.


2009 ◽  
Vol 2099 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Mark W. Burris ◽  
David H. Ungemah ◽  
Maneesh Mahlawat ◽  
Mandeep Singh Pannu

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