Implementation of an Automated Crack Sealer

摘要

Automated pavement crack sealing technology has been developed in the TxDOT- andFHWA-funded project described in this report. Performance of the prototype has been demonstrated, and the economics are attractive. A follow-up implementation and testing project involving field trials across the state has been approved. Automating crack sealing can reduce labor and road user costs, improve work quality, and decrease worker exposure to roadway hazards. Prior to the project described in this report, three interim studies at the University of Texas were completed. A study of methods, practices, and productivity for crack sealing in Texas complied detailed critical data. A study of methods, practices, and productivity for crack sealing in Texas complied detailed critical data. A study of sensor fusion methods led to the current tele-operated control strategy. And a study of maintenance automation needs based on surveys of TxDOT employees ranked automating crack sealing as one of the highest needs in the state. Approximately $200,000,000 is spent annually on crack sealing in North America. About 25 percent is privately contracted. In Texas, this rises to about 50 percent of the approximately $7,000,000 spent annually. Labor costs average between 50 percent and 60 percent total crack sealing costs. Parts for the system developed at UT are mostly off-the-shelf and total approximately $70,000. Additional costs for assembly, marketing and profit will require a sale price up to $125,000. Since approximately 3 laborers will be eliminated, the payback should be 1 to 2 years. According to the most recent economic analysis, if the automated crack sealing systems were implemented statewide, direct savings could amount to $2.43 million for TxDOT (at 4 percent MARR) and $2.64 million for private contractors (at 20 percent MARR) over a 6-year planing horizon. Using the widely accepted QUEWZ-E model, we estimated the user-cost savings to be $11.0 million for the 5,196 km of interstate highways in Texas. Total user-cost savings would be much higher, since the savings on urban freeways and streets, farm-to-market roads, and secondary roads are not included in this $11 million estimate. Over a 30-year planning horizon and from a national perspective, the net present worth of automated crack sealing could be in the humdreds of millions of dollars.