Estimating Transportation Impacts Fees

This paper will discuss how transportation impact fees are the contributions of investors in the cost of the needed infrastructure for their developments. The growth of Dubai during the past few years has been phenomenal. Accordingly, the need for highway infrastructure has been increasing rapidly. In order to provide some guidelines for calculating the transportation impact fees, Dubai‟s Roads & Transport Authority (RTA), issued Law #6 in 2006, provides the basis and legal cover for charging equitable impact fees for transportation projects to the beneficiaries of the projects. However, a detailed mechanism that covers the technical aspects in calculating impact fees is still not standardized in Dubai. The lack of clear procedure for calculating the transportation impact fees has created many disputes between RTA and transportation consultants in the city. The objective of this paper is to prescribe a cost-sharing mechanism and a transportation impact fee calculation method that are technically justifiable, equitable and proportional to the beneficiary parties and the government of Dubai represented by RTA. Six different procedures for transportation impact fee estimation were identified and tested. These procedures include the RTA proposed methodology or the “Development Trips/Total Volume” approach for distributing the cost of transportation projects in Dubai. Another is the proposed modified RTA approach, which is a variation of the RTA‟s traffic impact study manual. Others are transportation impact fee procedures discussed in the literature, including the facility-based approach, “Development Regional Impact (DRI) Trips/Capacity” approach, consumption-based approach and inductive fee approach. These procedures were tested on 15 different scenarios that representing different trip generation levels, and origin/destination trip combinations for the Business Bay project, a case study project in Dubai that has been selected to test the impact fee procedures in Dubai. Based on the results and analysis of the tests, the “DRI trips/capacity” approach is recommended for calculating transportation impact fees in Dubai because of its fairness, equitability and comprehensiveness to both RTA and developers.