Suggested Citation:
Naga, Raghavender Palavadi (2007) A Mathematical Model for Evaluating the Conversion of High Occupancy Vehicle Lane to High Occupancy/ Toll Lane . Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-07-20

A methodology for evaluating and quantifying the benefits/ costs of converting a given

High Occupancy Vehicle (HOV) lane into a High Occupancy/ Toll (HOT) lane is

presented in this study. A mathematical programming model that seeks the optimal

pricing strategy, using a logit-like choice model embedded as constraints, forms the core

of the methodology. A salient feature of this study is the incorporation of equity into the

planning process by imposing constraints thus enabling planners to limit the inequities in

vertical as well as temporal dimensions. A HOV lane on a corridor on I-80 in the San

Francisco Bay Area was studied for conversion under different objectives – revenue

maximization, total vehicular travel time minimization, total passenger time

minimization, total cost minimization and minimization of total vehicle miles traveled. It

was found that converting the HOV lane into a HOT lane would improve the objective

function in all programs except for total cost minimization. It was also found that the

capital and operating costs can be recovered in a reasonable amount of time (three-five

yrs). The analysis revealed that there can be significant differences in the pricing

strategies across different objective functions. The variation in the system performance

measures across different programs was also studied and it was found that revenue was

the most sensitive performance measure. The results of all the programs revealed that

there is an inverse relationship between equity and efficiency, with the exact nature of

this relationship being a function of the objective. Furthermore, in situations where there

is no redistribution of revenues, the vertical equity situation cannot be improved even

though all the user groups can be made better off after the conversion.

Additionally, Dynamic Programming models were constructed to solve for the optimal

sequence/ schedule of converting a given set of HOV lanes into HOT lanes. The optimal

sequences here minimized the total conversion time for a self-sustaining/ self-financing

sequence or minimized the total funding needed to complete all the conversions by a

certain deadline.