Design and evaluation of token-based reservation for a roadway system Kai Liu a , Edward Chan a , Victor Lee a,⇑ , Krasimira Kapitanova b , Sang H. Son b,c a Department of Computer Science, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong b Department of Computer Science, University of Virginia, Charlottesville, VA, USA c Department of Information and, Communication Engineering, DGIST, Daegu, Republic of Korea article info Article history: Received 31 December 2011 Received in revised form 24 July 2012 Accepted 3 September 2012 Keywords: Vehicular network Roadway reservation system Admission control Scheduling abstract Traffic congestion has become a major source of fuel waste, economic burden, environmen- tal pollution, and commuter frustration. A lot of effort has been made to alleviate these problems, but traditional countermeasures, such as expanding transportation capacity, are no longer a sustainable solution to the rapidly growing levels of congestion. Both gov- ernments and transportation planners are actively engaged in the development of traffic management strategies and policies, but their endeavors are not sufficient either. There- fore, it is imperative to further improve the efficiency of the existing road infrastructure by leveraging the latest technological advances in computing and networking. Recent stud- ies have shown that emerging technologies in vehicular networks have made the roadway reservation system a viable option for mitigating traffic congestion and improving trans- portation efficiency. In this paper, we present a roadway reservation system, where the drivers make reservations in advance in order to enter a high-priority lane. The drivers who successfully make the reservation are guaranteed certain quality of service, i.e. end- to-end travel delay. We propose a token-based reservation system which monitors and controls the traffic workload in real-time. We have also designed an on-line scheduling algorithm which maintains sufficient transportation efficiency by selecting which reserva- tion requests should be accepted. The algorithm also handles any necessary user interac- tion for reservation. A comprehensive performance evaluation based on our simulation model demonstrates the practicality and soundness of the proposed reservation system. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction The ever-expanding traffic congestion has seriously undermined the efficiency of current road transportation systems. Traffic has become a global problem and a major source of both economic and environmental problems. In the US, 439 urban areas are faced with serious congestion problems. In 2009, urban Americans wasted 4.8 billion hours in total during their travel and 3.9 billion gallons of fuel at cost of $115 billion due to congestion (TTI, 2010). In Japan, traffic congestion causes the loss of about 3.8 billion man-hours (worth about 12 trillion yen) each year (HandBook, 2006). According to recent stud- ies, about 11% of the fuel consumed by automobiles is wasted during congestion (Tsugawa and Kato, 2010). In addition to the extra fuel consumption, traffic congestion also causes the emission of higher levels of air pollutants and greenhouse gases, including carbon monoxide (CO), carbon dioxide (CO 2 ), hydrocarbons (HC), and oxides of nitrogen (NOx) (Servin et al., 2008). The U.S. Environmental Protection Agency reported that transportation accounted for approximately 33% of total CO 2 emis- sions from fossil fuel combustion, which is 7% higher than the share of industry (InventoryReport, 2011). 0968-090X/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.trc.2012.09.001 ⇑ Corresponding author. Tel.: +852 34428617; fax: +852 34420503. E-mail addresses: kailiu@cityu.edu.hk (K. Liu), csedchan@cityu.edu.hk (E. Chan), csvlee@cityu.edu.hk (V. Lee), krasi@virginia.edu (K. Kapitanova), son@dgist.ac.kr (S.H. Son). Transportation Research Part C 26 (2013) 184–202 Contents lists available at SciVerse ScienceDirect Transportation Research Part C journal homepage: www.elsevier.com/locate/trc