Assessing Impact of Bus Traffic on Pavement Maintenance Costs: City of Los Angeles

Engineers for the city of Los Angeles have observed that lanes carrying Mass Transit Authority (MTA) bus traffic deteriorate at a faster rate than similar lanes without bus traffic. The increased rate of deterioration results in greater maintenance costs in these lanes. To properly apportion the increased maintenance costs, city engineers need an objective method for quantifying the impact of MTA bus traffic. Multiple evaluation techniques are presented that may be used to quantify the effect of buses in terms of increased deterioration rates and greater rehabilitation costs. State-of-the-art techniques that use the results of deflection testing and pavement condition surveys are presented. Data collection procedures, methods for condition and structural analyses, and life-cycle costing procedures are provided. A case study that uses data collected from the city is presented. This study indicates an average yearly additional maintenance cost of $800 per lane-mile caused by MTA bus traffic, excluding associated costs for curb and gutter or maintenance hole adjustments.