Changmo Kim

Selection of Pavement for Highway Rehabilitation Based on Life-Cycle Cost Analysis: Validation of California Interstate 710 Project, Phase 1

Life-cycle cost analysis (LCCA) for highway projects is an analytical technique that uses economic principles to evaluate long-term alternative investment options, especially for comparing the value of alternative pavement structures and strategies. Recently, the California Department of Transportation (Caltrans) mandated LCCA implementation to evaluate the cost-effectiveness of pavement design alternatives for highway projects in the state. An LCCA approach was utilized for validation of the pavement design on the I-710 Long Beach rehabilitation project with three pavement types: innovative (long-life) asphalt concrete pavement (ACP), standard-life ACP, and long-life portland cement concrete pavement (PCCP). The LCCA followed the Caltrans procedure and incorporated information filed by the project team. The software tools Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) and RealCost were used for quantitative estimates of construction schedule, work zone user cost, and agency cost for initial and future maintenance and rehabilitation activities. Conclusions from the LCCA supported use of the innovative ACP alternative, the one actually implemented in the I-710 Long Beach project (Phase 1), since the innovative ACP alternative had the lowest life-cycle costs over the 60-year analysis period. For example, the life-cycle agency cost for the innovative ACP alternative (

Automated Work Zone Information System on Urban Freeway Rehabilitation: California Implementation

33.2 million) was about

Impact of Pavement Roughness on Vehicle Free-Flow Speed

7.9 million more cost-effective than that of the standard-life ACP alternative (

Value Analysis Using Performance Attributes Matrix for Highway Rehabilitation Projects: California Interstate 80 Sacramento Case

41.1 million) and about

Automated Sequence Selection and Cost Calculation for Maintenance and Rehabilitation in Highway Life-Cycle Cost Analysis (LCCA)

17.2 million less expensive than the long-life PCCP alternative (

Life cycle energy consumption and GHG emission from pavement rehabilitation with different rolling resistance

50.4 million). Utilization of the proposed computer tool–aided LCCA procedure would contribute substantial economic benefits to nationwide highway projects, especially rehabilitation and reconstruction.

Implementation of Automated Travel-Time Information and Public Reaction on Urban Highway Rehabilitation

In October 2004, about 9 lane km of deteriorated truck lanes on Interstate 15 at Devore in Southern California was rebuilt during 18 days with extended one roadbed full-closures with the counterflow traffic system and 24-h construction operations. The project implemented the automated work zone information system (AWIS) to reduce peak hour delay during construction by changing road users travel patterns and diverting traffic to detour routes. This paper describes the design, performance, and validation of AWIS with monitored traffic data before and during construction used. The AWIS was installed to provide road users with real-time travel information so that they could avoid traffic delays in the construction work zone (CWZ) corridor. Travel times through the CWZ were estimated from speed data and enhanced in two ways: (a) portable and permanent changeable message signs on site and (b) off-site (project website) implementation with travel time messages, traffic snapshots, and video streaming. AWIS trave...

UCPRC Life Cycle Assessment Methodology and Initial Case Studies for Energy Consumption and GHG Emissions for Pavement Preservation Treatments with Different Rolling Resistance

In earlier studies of the environmental impact of pavement roughness on life cycle greenhouse gas (GHG) emissions, it was assumed that pavement roughness (usually measured by International Roughness Index, IRI) has no impact on vehicle speed. However, because ride comfort increases when a pavement becomes smoother (that is, when roughness decreases), it is possible that people will drive faster on a smoother pavement. Because most vehicles achieve maximum fuel efficiency between 40 and 50 mph (64 and 80 km/h), fuel use increases at speeds beyond this range, and this increase in speed might offset the benefits gained from the reduced rolling resistance associated with reduced pavement roughness. Therefore, to investigate the impact of changes in pavement roughness on driving behavior with respect to speed, this study built a linear regression model to estimate free-flow speed on freeways in California. The explanatory variables included lane number, total number of lanes, day of the week, region (Caltrans district), gasoline price, and pavement roughness as measured by IRI. Data from the California freeway network from 2000 to 2011 were used to build the model. The results show that pavement roughness has a very small impact on free-flow speed within the range of this study. For the IRI coverage in this study (90 percent of the records have an IRI of 3 m/km or lower and 90 percent of the records have an IRI change of 2 m/km or lower), a change in IRI of 1 m/km (63 in./mi) resulted in a change of average free-flow speed of about 0.48 to 0.64 km/h (0.3 to 0.4 mph), a value low enough to cause almost no change in fuel use. This result indicates that making a rough pavement segment smoother through application of a maintenance or rehabilitation treatment will not result in substantially faster vehicle operating speeds, and therefore the benefits from reduced energy use and emissions due to reduced rolling resistance will not be offset by the increased fuel consumption that accompany increases in vehicle speed. However, efforts to develop a good model for predicting free-flow speed were not fully successful. The Southern California Interstate Freeway model developed yielded the best result with an adjusted Rsquared of 0.72. For the rest of the regions in the state, the selected explanatory variables can only explain about half of the total variance, meaning that there are still other variables, such as vehicle type, with a substantial impact on free-flow speed that were not covered in this study.

Enhancement of Life-Cycle Cost Analysis Tool: RealCost California Customization

Since 1997, when FHWA made value analysis (VA) a federal policy, the VA procedure has become necessary for improving pavement quality and reducing life-cycle and road user costs for highway projects, especially large-scale ones. The California Department of Transportation (Caltrans) has moved beyond simple compliance with the policy and implemented a new VA procedure in the planning and design stage of the Interstate 80 (I-80) Sacramento rehabilitation (planned to begin in 2011). This I-80 case study demonstrates an efficient new VA procedure and presents its results for three alternatives by using a performance attributes matrix (PAM) approach and Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) software. The PAM was used to quantify performance attributes, and CA4PRS was used to calculate the construction schedule and to estimate agency and user costs for each of the construction activities for a 60-year life cycle. The VA results show quantitative changes in performance and life-cycle costs for each alternative. On the basis of the VA teams recommendation, Caltrans adopted two of the three alternatives even though they required an increase of

Simulation of Annual Excess Fuel Consumption from Pavement Structural Response for California Test Sections

6.99 million in initial construction costs; however, the chosen combination of alternatives will provide a total savings of