Pavement and bridge cost allocation analysis of the Ontario intercity highway network

Abstract

Transportation infrastructure investments have important economic benefits for society and require a significant amount of public expenditure. Canadian road infrastructure carries more than 85% of total trips and consumes several billion dollars every year. Federal and provincial governments are responsible for providing the public with road services while trying to keep costs and taxes down. Hence, there is a pressing need to recover the road expenses by directly charging the road users in a rational way. The user charges, however, must be acceptable and direct the demand for road services in order to achieve an efficient utilization of the road infrastructure.

The objectives of this research are to examine the economic characteristics of the pavements and bridges of the Ontario inter-city highway network, to improve the procedures for cost allocation analysis, to calculate the rational road charges that should be levied on different vehicle types, and to analyze the effects of road prices and different pricing schemes on road users. These goals are achieved through a comprehensive analysis of pavement and bridge costs in Ontario based on the OPAC 2000 pavement performance models are well as some bridge cost estimating models and an innovative game-theoretic cost allocation approach developed in this research.

Significant differences are observed between cost characteristics of pavements with different subgrade and traffic conditions and in different locations of Ontario. Due to harsher climate in Northern Ontario pavement life-cycle costs are 6 to 15 percent higher than those in Southern Ontario. The life-cycle costs of optimally designed pavements with weak subgrades may be more than 60 percent higher than those with strong subgrades for the same location and traffic conditions. The cost analysis of Ontario pavements also implies that up to 70 percent of the deterioration of optimally designed pavements is due to environment-induced damage. Large differences are found between the pavement damages imposed by commercial trucks and passenger cars. The damage imposed by an overloaded truck trailer operating on a low volume road is estimated at about $1.61/km while an automobile operating on the same road imposes about $0.00000015/km. The overall life-cycle cost of the pavements in this study is estimated to be $2.18 billion. However, if the pavements were designed for automobile loads, that figure would be $1.38 billion. Hence, the large differences between the marginal cost of road use by commercial trucks and passenger cars do not justify the allocation of road charges to different road users in the same proportion of their marginal costs, since some of the road costs are common costs and roads are primarily designed to withstand truck loads.

The bridge cost analysis shows that the major element of bridge life-cycle cost is the initial capital cost of construction. The deterioration of bridges is largely due to environmental factors and deicing chemicals and maintenance costs are less than 0.2% of the initial construction costs. The bridge construction cost can be estimated at about $1000/m^2 (present worth) on average for most of the Ontario bridges. It is identified that the total bridge cost is about 14 percent of total road construction and maintenance costs in Ontario. The present worth of bridge construction costs for the bridge samples in the analysis database is estimated to be $10.8 billion, while this figure would be reduced to $5.5 billion if bridges were designed for automobile loads exclusively.

A new cost allocation procedure is developed based on the concepts of cooperative game theory. A set of rational relationships between vehicle costs are charges are established to reflect full road cost recovery and to ensure that no vehicle or group of vehicles is charged less than its marginal cost or more than its stand-alone cost. The game-theoretic approach provides flexibility, integrity, and transparency in observing the details of costs and prices under different road or taxation policies. On average across Ontario, the highest road fee for low and medium payload levels (1t to 30t) has been assigned to 3 and 4 axle semitrailers at $0.05/km followed by heavy haul A and B-trains at $0.04/km, 5+ axle semitrailers as well as 2 and 3 axle B-Trains at $0.03/km, single unit trucks (for 1t to 10t payload range) as well as single to tridem semitrailers at $0.02/km, and truck trailers at $0.01/km. For heavier payloads of more than 30t the highest road fee has been allocated to 3 and 4 axle semitrailers at $0.37/km followed by truck trailers at $0.24/km, 2 and 3 axle B-Trains at $0.20/km, 5+ axle semitrailers at $0.19/km, and heavy haul A and B-trains at $0.16/km.

The research also shows that vehicle operating costs dominate the total road user costs, limiting the effect of pricing strategies on efficient selection of vehicle type and payload level. The average vehicle operating cost is about $0.85/km, while the average road fee for trucks calculated in this research is about $0.06/km. It is also observed that if a complex pricing scheme through which vehicles are charged exactly the suggested game-theoretic prices were implemented, and if users reacted to such a pricing scheme in the most efficient way then the total savings in pavement life-cycle costs would be about 6 percent. It is concluded that the pricing tools may not be effective in directing the utilization of the road facilities to the most desirable level unless the collected fees are set above the total system cost or if the vehicle weight regulations are strictly enforced. However, proper pricing and taxation strategies can result in optimal selection of vehicles and would result in more efficient utilization of vehicle types.