High-occupancy Toll Lanes Research Articles

Measuring value of travel time and travel time variability in the presence of managed lanes: results from a pilot stated preference survey on the Capital Beltway

Managed lanes are roadways that have additional requirements placed on their usage in an effort to maintain reliable, uncongested flow. This concept is already gaining use in some parts of the United States where vehicles that do not meet the minimum vehicle occupancy requirements are allowed to use the high occupancy vehicle (HOV) lane with the payment of a fee, leading to the term, high occupancy toll (HOT) lanes. This study collects data on behavioral responses to managed lanes and in particular quantifies a traveler’s value of time in the hypothetical scenario that managed lanes are applied on the Maryland side of the Capital Beltway. The main purpose is to provide a data collection and evaluation framework to assess potential projects. Two stated preference (SP) surveys have been designed and executed. The first analyzes choice across normal lanes, HOT and HOV, proposing different components of travel time. The second is developed in a context of departure time shift and proposes uncertainty as a range. Results show that the second experiment was more successful in recovering work and non-work values of travel time, delivers significant results for the uncertainty coefficients, and reinforces the finding that later departure time is perceived more negatively than earlier departure time.

Development and comparison of choice models and tolling schemes for high-occupancy/toll (HOT) facilities

A high-occupancy/toll (HOT) lane is an increasingly popular form of traffic management strategy which reserves a set of freeway lanes for HOVs and transit users, while allowing low-occupancy vehicles (LOVs) to enter for a fee. In turn, HOT lanes maintain a minimal level of service by regulating the volume of entering LOVs. The focus of this paper is how to model the choice process of individual drivers, which dictates the volume of LOVs that choose to pay and take the HOT lane. Such models and the insights they provide can be very helpful for the toll setting process. Two simple formulations (an all-or-nothing assignment and an additive logit model) are compared with a proposed formulation based on the population value of time (VOT) distribution. Both static and dynamic toll setting algorithms are studied based on the proposed lane choice model, and their performance is compared under deterministic traffic behavior.

A unified framework of proactive self-learning dynamic pricing for high-occupancy/toll lanes

This article presents a unified framework to determine dynamic pricing strategies for high-occupancy/toll (HOT) lanes. The framework consists of two critical steps, system inference and toll optimisation. The first step is to mine traffic data in a real time manner to learn motorists’ willingness-to-pay, estimate traffic state and predict short-term traffic demand. The attained knowledge is then used in the second step to explicitly optimise toll rates for the next rolling horizon to maximise the freeway throughput while ensuring a free-flow travel speed on HOT lanes. This article discusses the details of each step and how to implement them. The framework is validated in a simulation environment based on a multi-lane hybrid cell transmission model. It is demonstrated that the framework is efficient, effective and flexible, and has the potential to be readily implemented in practice.

Model-Based Dynamic Pricing Algorithm for Managed Lanes

Managed lanes, or high-occupancy toll (HOT) lanes, have been implemented across the United States to improve the utility of existing road facilities. The pricing algorithm in managed lanes is the critical component in ensuring that the desired level of service metrics is met. Some pricing algorithms currently in use are static algorithms, and others adopt a dynamic strategy. Static pricing algorithms do not account for the changes in real-time traffic conditions. However, dynamic pricing algorithms are reactive in nature and do not account for the potential demand for actual future time intervals for which the toll is determined. The HOT-lane system is nonlinear and complex in nature; this complexity leads to high levels of instability in such a system. The complexity has been increasing because of the growth in demand as well as incorporation of other, noninteracting strategies that are implemented to address this demand. Therefore, more sophisticated designs of the pricing algorithm are needed for HOT-lane pricing control. A model-based pricing algorithm is proposed for determining the toll rate dynamically to maximize the throughput on the HOT lanes while maintaining a desired level of service. It consists of both proactive and reactive components to achieve fast response to real-time changes and maintain a steady, maximal traffic flow. The controller structure also incorporates active bottleneck management to maintain optimal traffic flow under stressed conditions. Implementation of this controller has shown high utilization of HOT lanes while ensuring the desired level of service.

Impacts to Transit from Variably Priced Toll Lanes

This paper describes the impacts on transit performance from three separate conversions of high-occupancy vehicle lanes into variably priced high-occupancy toll (HOT) lanes in Miami, Florida; Minneapolis, Minnesota; and Atlanta, Georgia. The data showed that the conversions had no negative impact on bus performance. In all three cities, the buses experienced travel time savings after the conversion: 17 min in Miami, 4.5 min in Minneapolis, and 5 min in Atlanta. Similarly, the HOT conversions did not negatively affect bus ridership. Ridership increased over the baseline by 57% in Miami and 13% in Minneapolis. In Atlanta, ridership increased by 11%, and this increase began before the conversion. Bus riders’ overall perception of the HOT lanes has been positive. In surveys, the bus riders from Miami and Minneapolis gave high ratings for travel times and reliability in the HOT lane corridors. Riders in Atlanta rated the bus service as very good but were not as positive about the tolls. Riders disagreed that the HOT conversion had improved their travel or been good for the Atlanta region. These negative responses may be attributable in part to widespread disgruntlement with the HOT concept that existed even before implementation.

Simulating High-Occupancy Toll Lane Operations

Microscopic simulation is critical for evaluating the operation strategies of managed lanes. However, most existing tools are limited in their ability to simulate dynamic tolling strategies of managed lanes, particularly those with multiple segments. Three sets of modeling components are developed in this paper to demonstrate simulation of high-occupancy toll (HOT) lane operations. The first component implements three pricing strategies: responsive pricing; a closed-loop, control-based algorithm; and time-of-day pricing. The second component mimics drivers’ lane choice behaviors in the presence of tolls, and the third represents different toll structures for multisegment HOT lane facilities. An enhanced version of CORSIM, which contains these new modeling components, is validated by simulation experiments involving the 95 Express network in South Florida.

Valuation of travel time reliability from a GPS-based experimental design

In the Minneapolis–St. Paul region (Twin Cities), the Minnesota Department of Transportation (MnDOT) converted the Interstate 394 High Occupancy Vehicle (HOV) lanes to High Occupancy Toll (HOT) lanes (or MnPASS Express Lanes). These lanes allow single occupancy vehicles (SOVs) to access the HOV lanes by paying a fee. This fee is adjusted according to a dynamic pricing system that varies with the current demand. This paper estimates the value placed by the travelers on the HOT lanes because of improvements in travel time reliability. This value depends on how the travelers regard a route with predictable travel times (or small travel time variability) in comparison to another with unpredictable travel times (or high travel time variability). For this purpose, commuters are recruited and equipped with Global Positioning System (GPS) devices and instructed to commute for two weeks on each of three plausible alternatives between their home in the western suburbs of Minneapolis eastbound to work in downtown or the University of Minnesota: I-394 HOT lanes, I-394 General Purpose lanes (untolled), and signalized arterials close to the I-394 corridor. They are then given the opportunity to travel on their preferred route after experiencing each alternative. This revealed preference data is then analyzed using discrete choice models of route. Three measures of reliability are explored and incorporated in the estimation of the models: standard deviation (a classical measure in the research literature); shortened right range (typically found in departure time choice models); and interquartile range (75th–25th percentile). Each of these measures represents distinct ways about how travelers deal with different sections of reliability. In all the models, it was found that reliability was valued highly (and statistically significantly), but differently according to how it was defined. The estimated value of reliability in each of the models indicates that commuters are willing to pay a fee for a reliable route depending on how they value their reliability savings.

High Occupancy Toll Lane Performance Under Alternative Pricing Policies

This paper explores how alternative pricing and operating policies influence revenue generation, level of service, and travel time costs for high occupancy toll (HOT) lane facilities. A framework for modeling HOT lanes is applied to a hypothetical facility. The analysis suggests that the way in which tolls are set can have a non-trivial influence on competing measures of HOT lane performance. Other operating characteristics, such as the number of lanes designated as free and priced and whether carpools are allowed to ride free or must pay a toll to access the HOT lanes, are shown to significantly influence performance as well.

On the Impact of HOT Lane Tolling Strategies on Total Traffic Level

This paper shows how tolling (or pricing) strategies can be used to control the congestion levels of both untolled and high occupancy toll (HOT) lanes. Using a user-equilibrium method, the paper calculates the number of travelers on each route during the peak period and provides a numerical analysis that determines the distribution of travelers for different tolling strategies. It shows that with the right tolling strategy some travelers who initially plan to use the untolled lane during the peak period will change both their routes (i.e., select the HOT lane) and departure times (i.e., depart earlier or later). Using this result, the paper compares static and dynamic pricing strategies and shows that with a dynamic strategy a larger profit can be earned and congestion reduced in the untolled lane.

Generating Revenue to Fund Public–Private Partnerships for Reconstruction of Freeway Systems in Metropolitan Areas

The multimodal expressway concept proposed in this study involves creating a network of high-occupancy toll (HOT) lanes and managing traffic at greater distances from the congested hot spots to relieve the flow-exacerbating impacts on the hot spots. Modal choices for customers are created along with pricing and parking strategies. HOT lanes would not only serve cars but would also become bus rapid transit lanes. Managers would be able to use real-time pricing, speed controls, modal shifts, and information systems to regulate traffic flows throughout the region. The HOT-lane network would be created by reconfiguring the existing freeway footprint to accommodate new HOT lanes by using a portion of the left and right shoulders and restriping of regular lanes into narrower lanes if needed, along with creation of emergency pull-off areas. To encourage transit, the HOT lanes would have a progressively increasing passenger mile performance measure in a public–private partnership agreement. Sketch-planning analysis is used to assess the potential of this strategy to address funding needs for public–private partnerships for freeway reconstruction in a prototypical large U.S. metropolitan area. Potential public concerns about tolls and ways to address them are also discussed. The results from the case study sketch-planning analysis suggest that revenue from the HOT-lane network, when supplemented with revenue generated through gas taxes and other fees paid by users of the highway network, would be sufficient to pay for the reconstruction of the freeway system in the case study area.

Operational Performance and Speed–Flow Relationships for Basic Managed Lane Segments

Managed lane facilities, including high-occupancy vehicle (HOV) lanes, high-occupancy toll lanes, and express lanes, have become attractive tools for managing today's transportation system. Although managed lanes, specifically, HOV lanes, have existed for several decades, there has been little documentation of their traffic flow behaviors. Because these facilities tend to take on a variety of configurations, including different numbers of managed lanes and separation types from abutting general purpose lanes, transportation engineers should understand the traffic flow differences among facility types. An understanding of the interaction between managed lanes and parallel general purpose lanes is also needed for assessing the performance of managed lanes. A study was done to investigate the performance and traffic flow behavior of managed lane facilities at sites across the country. Traffic flow behavior for five facility types, based on separation type and number of lanes, was analyzed. Factors such as frictional impact on the managed lane—caused by poor performance of the general purpose lanes and slow vehicle effects on managed lane facilities where passing is prohibited—were considered in development of a set of speed–flow curves for each of the five basic facility types. These speed–flow relationships are expressed similarly to basic freeway segments in the Highway Capacity Manual and can be readily incorporated into the manual for predicting the performance of combined general purpose and managed lane facilities.

Development of Active Management Screening Tool

This paper summarizes an FHWA-directed project for the development of an active management screening tool (AMST) for agencies with congestion management process planning tools. The purpose of the AMST is to help those agencies better assess the potential of active management strategies for their region within the congestion management process. Furthermore, the AMST is structured to provide beneficial information and general guidance related to active management strategies in all areas and levels of transportation planning. The tool directly links the transportation planning process with operations by providing regional managers with information about operational strategies that they may find most beneficial to include in their plan for the regional transportation network. The AMST ascertains, at the appropriate screening level, major attributes about candidate corridors that help determine the suitability and appropriateness of an active management strategy. In successive steps the AMST ascertains the best strategy and its companion support that will enhance the facility's and program's responsiveness to the mobility, safety, and environmental needs of the corridor. Active management strategies included in the tool are high-occupancy vehicle lanes, high-occupancy toll lanes, express toll lanes, nontolled express lanes, exclusive or dedicated truck lanes, exclusive transitways, temporary shoulder use on freeways, speed harmonization, queue warning, dynamic rerouting and traveler information, ramp metering, dynamic merge control, and automated enforcement.

Performance Evaluation of I-394 MnPASS Express Lanes in Minnesota

In 2005 the Minnesota Department of Transportation (DOT) implemented the state's first optional toll lane project, the I-394 MnPASS Express Lanes. Located in the western half of the Minneapolis–Saint Paul metropolitan area, the MnPASS Express Lanes project converted underperforming high-occupancy vehicle lanes on Interstate 394 into high-occupancy toll lanes that allowed solo drivers the opportunity to pay an electronic fee to bypass congestion. After more than 5 years of operational experience, Minnesota DOT conducted an evaluation to determine whether MnPASS Express Lanes have met performance expectations and goals. The results of this analysis indicate that the lanes are performing efficiently, are continuing to ensure free-flow speeds for all users, and are enhancing vehicle and person throughput. In addition, the lanes generate sufficient revenue to cover operational costs. A recent survey indicates that MnPASS Express Lanes are providing users with value for their money in time savings and overall customer satisfaction.

Vehicle Class–Specific Route Guidance of Freeway Traffic by Model-Predictive Control

Few active traffic management measures proposed in the past considered the distinction of different vehicle classes. Examples of measures specific to vehicle class are truck lanes and high-occupancy toll lanes. It is proposed that the distinction of different vehicle classes, with different flow characteristics and societal and economic functions, can contribute to the effectiveness of traffic management measures. This study developed a multiclass controller that rerouted the traffic class specifically. Vehicle class–specific properties such as vehicle length and value of time were used in a model-predictive control approach to minimize the total time spent in the network by vehicles and the corresponding economic costs. By means of a simple test case with synthetic data, it was shown that a multiclass controller outperformed a single-class controller and that the multiclass control signals were sensitive to the value of time and the capacity of the network.

Sensitivity of Commuters’ Demographic Characteristics to License Plate Data Collection Specifications: Case Study of I-85 High-Occupancy Vehicle to High-Occupancy Toll Lanes Conversion in Atlanta, Georgia

The demographic characteristics of commuters are significant determining factors in many transportation-related policy and planning decisions. A popular way of obtaining the demographic characteristics of roadway system commuters is through license plate studies. There is a concern, however, that data collection factors including time, day, and location of data collection can potentially affect the observed demographic characteristics of the collected samples. This study uses statistical tests to assess the sensitivity of observed demographic characteristics from license plate data collection to data collection parameters by using data collected in the I-85 high-occupancy vehicle corridor in the Atlanta, Georgia, metropolitan area.

Willingness to Pay for High-Occupancy Toll Lanes

This research examined the willingness of travelers to pay for travel time savings (TTS) on the I-394 MnPASS express lanes in Minneapolis, Minnesota, and the I-15 express lanes in San Diego, California. The findings from both facilities indicate that many travelers are willing to pay a toll for a small TTS. The revealed preference values of time for the I-394 paying customers averaged $73/h in the morning and $116/h in the afternoon. Travelers on the I-15 express lanes received slightly higher TTS than on the I-394 and typically had a lower willingness to pay. Their revealed preference values of time averaged $49/h in the morning and $54/h in the afternoon. On the basis of the magnitude of these values, it is likely that travelers are paying for more than just TTS, possibly travel time reliability also. This finding means that these lanes likely have added value to travelers beyond time savings. The variability of the dynamic toll prices on the I-394 MnPASS express lanes in Minnesota and the I-15 express lanes in San Diego was also examined. Toll rates during the morning and afternoon peak hours varied considerably, with tolls ranging from $0.50 to $8.00. Conversely, off-peak times showed little to no variation. These trends were similar for different days of the week, and even from year to year. These trends were common across both I-394 and I-15 express lanes, although more variation was found on I-15. Tolls varied little during off-peak periods.

Managed Arterials

Priced managed lanes have been proposed and implemented exclusively on limited-access roadways. Yet major arterials handle a large fraction of urban traffic and account for a significant portion of traffic congestion. This paper proposes a way to apply priced congestion relief to major arterials (six or more lanes) and builds on research from the early Value Pricing Pilot Program on tolled queue jumps (grade separations) at signalized intersections, carried out in Lee County, Florida. A “managed arterial” (MA) is defined as an arterial retro fitted with a series of electronically tolled grade separations (overpasses or underpasses) that provide an alternative to the signalized intersection for through traffic. Bus rapid transit is an important element of the concept, and the MA provides an alternative to arterial bus-only lanes, similar to high-occupancy toll lanes providing an alternative to bus-only lanes on freeways. The study addresses issues and trade-offs in integrating bus rapid transit into the design and operation of MAs. The study includes conceptual designs of overpasses and underpasses for use in MAs and estimates the throughput increase obtained by converting a six-lane arterial to the MA configuration compared with that provided by widening it to eight lanes. Sketch-level estimates of financial feasibility are included.

Evaluation of Operational Effects of Joint Managed Lane Policies

AbstractThis paper presents a method to evaluate the operational effects of managed lane policies—vehicle eligibility, access control, pricing, and the number of managed lanes—that form a policy combination set. Two macroscopic methods are developed to prescreen the set via simple criteria, followed by integer linear programming with multiple objectives and constraints to identify the noninferior policies among the downsized set. The approach is demonstrated on the Southern California SR-57 corridor. The application eliminates twelve of possible twenty policy combinations by the macroscopic methods, and generates four noninferior policies—the existing high-occupancy vehicle lane operation and three additional potential high-occupancy toll lane policies—in terms of maximum vehicle and passenger throughput, minimum vehicle hour traveled, and travel time variance. The prescreening efficiency of the macroscopic stage, ranging from 0 to 95%, is affected by the initial policies and traffic conditions. It is con...

Hot lane policies and their implications

This research examined the major changes in a corridor due to high occupancy/toll (HOT) lane implementation. This was accomplished by comparing the impacts of HOT lanes on three pairs of HOT lanes with similar design and operational characteristics. These pairwise comparisons of similar HOT lanes reduced the impact of exogenous factors and removed the issue of comparing HOT lanes that were so dissimilar it would be impossible to isolate the reasons for difference in results from the lanes. With strict registration requirements for free high occupancy vehicle (HOV) 3+ travel on the I-95 Express Lanes (ELs) in Miami there were indications that some carpoolers switched to lower occupancy modes. Tolled access for HOV2s on I-95 and the SR-91 ELs near Los Angeles resulted in lower usage of those ELs by the HOV2s as compared to most HOV lanes where HOV2 access is free. On the SR167 (Seattle) and I-25 (Denver) HOT lanes, exogenous factors like the price of gas and the economic recession seemed to be the primary influence on the usage of those HOT lanes. In both cases, carpool usage increased along with the price of gas. On I-25, the increasing unemployment rate coincided with a decrease in toll paying travelers. On SR 167 there were also indications of mode shifts among the transit, carpool and toll paying SOVs due to the fluctuating price of gas.

Empirical evidence from the Greater Toronto Area on the acceptability and impacts of HOT lanes

This paper describes a study on willingness to pay (WTP) and public acceptability for High-Occupancy/Toll (HOT) lanes using empirical evidence from Toronto, Ontario, Canada. From a stated preference survey of more than 250 drivers, we estimate mean willingness to pay values under various trip conditions and for various traveler characteristics. The study provides statistically significant evidence on the relationships between willingness to pay and the improvement in travel speeds in HOT lanes, the length of the trip, and the urgency of on-time arrival. Furthermore, our study confirms several literature findings from previous studies on the relationship between travelers' willingness to pay and income as well as prior experience with HOT lanes. Some of the findings are qualitatively validated on the basis of the observed travel behavior in choosing tolled facilities over untolled facilities during periods of heightened congestion and urgency.