Estimating congestion toll by using traffic count data — Singapore's area licensing scheme

There are many studies on the Area Licensing Scheme in Singapore. One of the debatable issues is whether or not the congestion toll of $3 is too high. The main objective of this paper is to develop a simple method for estimating the congestion toll by directly using the commonly available traffic count data. In our sensitivity analysis, we use three different scenarios on the choice of the value of travel time savings and four different measures of average wage rates (the national average wage rate the average wage rate for car owners with or without taking into consideration of employment benefits, and the average wage rate per car derived from the average occupancy per car). The sensitivity analyses led to a general conclusion that by 1990, the $3 fee was not too high. We also highlight the fact that it is possible to iterate to the optimal congestion toll by comparing the theoretical congestion toll with the actual toll even when the demand curve is unknown. ©     

A model for a multi-size inland container transportation problem

In the multi-size Inland Container Transportation Problem (mICT) trucks are able to transport up to two 20-foot or one 40-foot container at a time along routes with various pickup and delivery locations. A mixed-integer linear program for the mICT is presented using two alternative objective functions: minimization of the total travel distance and minimization of the total operation time of the trucks. The presented model is tested on instances which vary in size. Computational experiments show that by means of the presented model small problem instances can be solved optimally.     

A novel modeling approach for the fleet deployment problem within a short-term planning horizon

This paper is concerned with model development for a short-term fleet deployment problem of liner shipping operations. We first present a mixed integer nonlinear programming model in which the optimal vessel speeds for different vessel types on different routes are interpreted as their realistic optimal travel times. We then linearize the proposed nonlinear model and obtain a mixed integer linear programming (MILP) model that can be efficiently solved by a standard mixed integer programming solver such as CPLEX. The MILP model determines the optimal route service frequency pattern and take into account the time window constraints of shipping services. Finally, we report our numerical results and performance of CPLEX on randomly generated instances.     

The path and time efficiency of residents' trips of different purposes with different travel modes: An empirical study in Guangzhou,China

Improving residents' travel efficiency and reducing carbon emissions from travel are the key issues for sustainable development of urban transportation. This study first employed a circuity index to measure the path efficiency of residents' trips based on 2015 survey data in Guangzhou and developed a generalized additive model (GAM) to investigate the relationship between the path efficiency and travel distance for different purposes of trip and different travel modes. On this basis, it further evaluated the time efficiency of different travel modes for each trip. The results showed that there is a complex and nonlinear relationship between the path efficiency and travel distance, which differs between different purposes of trips and different travel modes. In general, trips by non-motorized transport have a lower circuity index and higher path efficiency than those by cars or public transport. Moreover, non-motorized transport is the time-efficiency optimal mode for almost half of the trips, especially for daily shopping trips. However, people prefer to choose public transport on their trips even though public transport is not the time-efficiency optimal mode for these trips. Generally, only about half of the residents chose the time-efficiency optimal mode for their trips. Those who did not choose the time-efficiency optimal mode tended to choose the modes with higher carbon-intensity. The conclusions of this study indicate that for improving travel efficiency and reducing carbon emissions from transport, more efforts should be focused on the non-motorized travel environment and developing relevant policies to encourage more walking and cycling.     

Transportation network reliability in emergency response

Distribution of humanitarian supplies is vital in saving lives during disasters. Investment in retrofitting critical transportation links reduces casualties as intact links improve flow of relief supplies. In finding critical links, link importance values are derived using the concept of network reliability. A network improvement problem is then solved to minimize death toll. To increase practicality, a heuristic algorithm is proposed to solve real size problems. Results show that initial incremental investments in network improvement are more profound in reducing the death toll than higher budget increments. Moreover, higher relief inventories reduce the death toll when the network is reliable.     

Location quotient-based travel costs for determining accessibility changes

Accessibility is not a static feature because it is affected by a large number of factors, such as changes in transport infrastructure, the spatial distribution of human activities, and their interdependence. In this study, we examine the role of location quotient-based travel costs as the travel impedance function in accessibility measurement to better capture accessibility changes over time. The travel impedance function is one of the most widely studied aspects of accessibility. In most studies, travel impedance is determined by a negative exponential function in the travel cost assessment of the accessibility measure as a means to incorporate the distance decay effect. Here, we apply an accessibility index that uses location quotient-based travel costs and an accessibility measure with simple travel costs in order to test the proposed theory. The results of the two methods vary considerably. The location quotient method is discussed in detail, including its potential advantages for measuring accessibility changes. We argue that the location quotient-based travel cost is an appropriate method for determining the travel impedance function in accessibility measurements, especially for analyzing accessibility changes.     

Bergen light rail – Effects on travel behaviour

Bergen is the second most populous city in Norway (280,000 inhabitants) and is situated along the west coast of the country. In 2010, the city reintroduced tram service with the opening of a new light rail line, after a gap of 45 years. This study documents the increase in public transit use in Bergen, both in terms of volume and market share, since the line was opened. Furthermore, it explores the effects of light rail transit on travel behaviour using Bergen as a case city. These goals are accomplished by combining and analysing data from different sources, including five travel surveys, and other data concerning building stock, population, business activity, commuting and traffic counts. The study identifies four potential driving forces for changes in travel behaviour: (1) the introduction of the light rail; (2) a new high-frequency bus network; (3) increased rates in the toll cordon system; and (4) changes in the urban structure. The study concluded that the introduction of light rail was the main driving force behind the growth in public transit use. The study also highlighted that transit use was highest in areas served by the light rail. The effects of the light rail investments are reinforced by an optimal location of the line with respect to potential users.     

Discrete choice models of traveler participation in differential time of day pricing programs

Tolls that vary based on time of day or congestion are gaining attention around the world as a potential travel demand management strategy that can shift peak period travel to off peak periods thereby contributing to peak period congestion relief. However, despite the widespread interest in the concept, there is very little empirical data available on the impacts of variable tolls on traveler choices and disaggregate models that can be used to predict traveler response to variable pricing are few. This paper reports on results from two bridges with differential time of day tolls in the Lee County area of Florida in the United States. Using travel survey data collected at these two bridges, discrete choice models of traveler response to the variable toll rates are estimated. The models indicate that travelers who are retired, have a low income, have flextime at their place of employment, or have a flexible travel schedule are more likely to alter their time of travel with greater frequency due to the variable toll.     

Optimizing road network daily maintenance operations with stochastic service and travel times

This paper studies optimization methods for a routing problem encountered in daily maintenance operations of a road network. Stochastic service and travel times on road segments are considered. The problem is formulated as a variation of the capacitated arc routing problem (CARP). A chance-constrained programming model is firstly developed and solved by a branch-and-cut algorithm. A stochastic programming model with recourse is also proposed to take into account the recourse costs in case of route failure. The problem is solved by an adaptive large neighborhood search algorithm. The computational experiments demonstrate the effectiveness of the algorithm.     

Evaluation of access to health care in rural areas using enhanced two-step floating catchment area (E2SFCA) method

The study concerns with the quantification of accessibility to health facilities which is a prime concern in rural areas. In order to assure access to health care, planning commissions and policy decision makers require definite and reliable measures of accessibility values, thus that appropriate health care shortage areas can be analyzed and a policy decision can be taken accordingly to pacify the problem. Thus in this paper enhanced two step floating catchment area (E2SFCA) method, a special case of gravity model is used to quantify the present accessibility levels to health in rural areas. E2SFCA method which is an enhancement of two step floating catchment area (2SFCA) method differentiates the accessibility of the population within the catchment area by introducing a distance decay function. At the point when calibrating the distance decay from the travel behavior of patients in the study areas, it is revealed that sigmoidal functions are more likely suitable for the high population density regions and also plain terrains and decline functions for low population density regions and difficult desert or hilly areas. The paper yields health care shortage areas.     

An exploratory analysis of relationships between socioeconomic,land use,activity participation variables and travel patterns

This paper aims to find relations between the socioeconomic characteristics, activity participation, land use patterns and travel behavior of the residents in the São Paulo Metropolitan Area (SPMA) by using Exploratory Multivariate Data Analysis (EMDA) techniques. The variables influencing travel pattern choices are investigated using: (a) Cluster Analysis (CA), grouping and characterizing the Traffic Zones (TZ), proposing the independent variable called Origin Cluster and, (b) Decision Tree (DT) to find a priori unknown relations among socioeconomic characteristics, land use attributes of the origin TZ and destination choices. The analysis was based on the origin–destination home-interview survey carried out in SPMA in 1997. The DT application revealed the variables of greatest influence on the travel pattern choice. The most important independent variable considered by DT is car ownership, followed by the Use of Transportation “credits” for Transit tariff, and, finally, activity participation variables and Origin Cluster. With these results, it was possible to analyze the influence of a family income, car ownership, position of the individual in the family, use of transportation “credits” for transit tariff (mainly for travel mode sequence choice), activities participation (activity sequence choice) and Origin Cluster (destination/travel distance choice).     

Modelling and evaluation of road pricing in Paris

This article describes the impacts of road pricing in Ile-de-France, a region that includes Paris. The morning peak is studied using METROPOLIS: a dynamic network simulator that treats endogenously travellers' mode, departure time and route-choice decisions. Time-independent tolls on selected links, time-varying cordon tolls, and a network-wide toll proportional to travel time are considered. Welfare gains from the link and cordon tolls are relatively small. The comprehensive travel-time-based toll yields much higher benefits. In all cases, benefits to users amount to a large fraction of toll revenues and exceed the monetised value of reductions in noise, accidents and vehicle emissions.     

A multi-objective approach to scheduling joint participation with variable space and time preferences and opportunities

Activity scheduling supports activity-based analysis in travel demand management and promotes a potentially popular traveler assistance service. A multi-objective approach is proposed to schedule joint participation of multiple individuals, in which the candidate space-time opportunities for joint participation are identified by a concept of time-varying network-based prisms, and optimal opportunities for joint participation are determined by the non-dominated sorting genetic algorithm-II (NSGA-II) with four objectives (i) minimizing cost for congestion charges, (ii) maximizing participation desirability of time-of-day, (iii) minimizing total travel distance and (iv) time in the trips of multiple individuals. A scenario of joint participation among four people is designed and implemented to demonstrate the feasibility of this approach. The results suggest that this approach has the ability to schedule activities within real situations.     

The hierarchy of roads, the locality of traffic, and governance

This study investigates the use of road networks both within and outside of home jurisdictions (city (or town) and county of residence) by analyzing GPS data collected in the Minneapolis—Saint Paul metropolitan area. The study tracked volunteers' travel behavior to determine which roads (and thus which class of roads) users chose to accommodate their travel needs. More than half of the travel on county roads and city streets occur outside of one's home city, but most travel is within one's home county. The average share of travel distance in the home county is more than 70% for both county and city streets. The high share, which does not account for non-residents destined for the county to work or shop, e.g., implies that the free rider problem on city and county streets at the county level is minimal. Of particular concern is travel on city roads in cities other than one's own. To the extent that this is to go to a destination in that city, that travel is also local. However, because city and county roads are typically funded by those jurisdictions from land-based sources such as property taxes, through trips with neither end in the city through which they are traveling are in a very real sense “free riders”, and pose a problem. With growing trip lengths and emerging economies of scale in road management, it may be appropriate to consider moving more roads from township, town, or city level to the county level of government.     

Congestion tolls and parking fees: A comparison of the potential effect on travel behavior

This paper presents a comparison of attitudes towards congestion and parking tolls and explores their effect on travel behavior. The findings indicate that drivers are sensitive mainly to congestion tolls and are willing to change their travel habits to avoid these tolls. The major effect of a congestion toll is the shifting of the time of the journey. High levels of demand elasticity (−1.8 for congestion tolls and −1.2 for parking fees) were found. The readiness to pay parking fees is greater; thus, the effectiveness of congestion tolls in reducing demand is higher during the times the tolls apply.     

Flat versus spatially variable tolling: A case study in Fresno,California

A number of studies have examined the feasibility of temporal variations in tolls. However, spatial variation in tolls has not received much attention, especially in practice. Spatial variation could effectively reduce congestion and increase profits. To fill this gap, we conduct an empirical application on 3 different road segments using the Fresno, California's transportation planning model. Our modeling results in a number of interesting insights. First, the derived optimal flat toll values are very close to the average variable tolls, but the effects of applying spatially variable tolls on improving total revenues (from 4% to 24%) and total improved travel time (from 18% to 1083%) measures are significant. Second, spatially variable tolls are more effective, but more costly, particularly for arterials, which can be attributed to the higher number of access points for arterials. Third, spatial variations in tolls are more effective for peak hours than for off-peak hours and for social optimization than for profit maximization. Fourth, to improve throughputs for both profit maximization and social optimization, the prevalent tolling pattern along a corridor induces lower final volumes per capacity (V/Cs) (after pricing) at the mainline flow sections and relatively higher final V/Cs at the entrance and exit (boundary) points. Finally, optimal toll patterns are not dependent on vehicle miles traveled (VMTs) or volumes but, rather, are related to targeted V/Cs. Therefore, flow-dependent charges along a corridor should be based on V/Cs rather than on volumes or VMTs.     

Urban transport pricing reform with two levels of government: A case study of Brussels

This paper analyses two challenges in the reform of urban transport pricing. First the construction of an optimal package of urban transport pricing instruments assuming one benevolent welfare maximizer. It is found that parking and tolling are the most important elements of the optimal package and that these policy instruments are sub-additive in their benefits. The second problem is the use of pricing instruments by different government levels: the urban government controls parking fees and the regional government controls a cordon toll. It is found that the overall efficiency losses in the Nash and Stackelberg equilibria are limited.     

Evaluating the reliability of reported distance data in urban travel behaviour analysis

The objective of the present paper is to analyze the accuracy of reported distances in travel behaviour research, and to distil from this analysis some useful recommendations for data collection and handling in activity-based modelling. This issue is important because we know from the literature on distance cognition that conjecture, perception and rounding in distance reporting is a rule, rather than an exception. The outcome is a biased transport modelling result. The paper introduces some theoretical reflections on distance measurements and cognition. Next, using household travel survey data collected in 2000 for the city of Ghent, Belgium, the problem of reported distance reliability is examined. A comparison of travel distances using detour factors revealed that self-reported distances provide reasonable estimates of shortest distance path distances. With respect to the effect outliers and rounding have on the reliability of reported distances it is found that mean detour factors are very much dominated by outliers over short distances, but that rounding has little impact. The accuracy of self-reported distances is also influenced by the socio-demographic profile of the respondents, the characteristics of the trip, and the type of transport mode used.     

A method for quantifying travel productivity for corporate travel managers

For large corporations with significant travel budgets, the efficiency in execution of employee travel is critical to the productivity of the enterprise. Air travel disruptions (i.e. delays, cancellations, missed connections) prevent employees from performing enterprise related tasks resulting in lost billable revenue and unbudgeted Indirect costs (e.g. unplanned overnight stays for stranded passengers, and idle time charges). Since travel disruption data is not readily available to Corporate Travel Managers, the Indirect charges cannot be included in budgets, and the magnitude of lost billable revenue is not known. Further, without measuring the travel delays and their impact, it is not possible to understand the underlying causes of the delays to improve the process.This paper describes a method for providing Corporate Travel Departments travel disruption statistics and their impact on revenue and profits. The method overcomes the problem of the absence of data by deriving travel delay statistics for corporate travel from publicly available historic airline flight data-bases. The method also uses a travel delay cost model to estimate the financial impact of travel disruptions. The implications of these results on Corporate Travel Management (CTM) productivity improvement strategies, corporate travel and indirect budgets, contracts with travel providers, and travel insurance are discussed.     

Pay to drive in my bus lane: A stated choice analysis for the proposed Lincoln Tunnel HOT lane into Manhattan

This paper presents the findings from a stated choice (SC) analysis conducted in the context of proposed changes to the lane system in use for the Lincoln Tunnel crossing into Manhattan. Currently, the approach road (NJ 495) to the Lincoln Tunnel has six lanes, with three in each direction. During the weekday morning peak period, The Port Authority of New York and New Jersey (PANYNJ) operates a 2.5 miles exclusive bus lane (XBL) for traffic bound for Manhattan. The PANYNJ is considering creating, from existing lanes, a second XBL with the option for passenger vehicles to use it in return for an additional toll, in effect turning it into a high occupancy toll (HOT) lane. Such an approach to increase capacity and reduce congestion is unique nationally and this study looks at drivers' choices between using standard lanes, paying extra to drive on a HOT lane (the new XBL lane), switch to earlier or later departure times, or change their mode of travel. The analysis shows significant differences in the valuation of travel time savings between different population groups and also different departure time periods. The models also reveal a reluctance to change to other crossings, accept changes in departure time or switch to alternative modes.