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Abstract:
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The Texas Department of Transportation (TxDOT ) uses the Texas Condition Assessment Program (TxCAP ) to measure and compare the overall road maintenance conditions among its 25 districts . TxCAP combines data from three existing subsystems : the Pavement Management Information System (PMIS ) , which scores the condition of pavement ; the Texas Maintenance Assessment Program (TxMAP ) , which evaluates roadside conditions ; and the Texas Traffic Assessment Program (TxTAP ) , which evaluates the condition of signs , work zones , railroad crossings , and other traffic elements to get an overall picture of the condition of state roads . As a result , TxCAP provides a more comprehensive assessment of the interstate and non -interstate highways . However , the scores for each of the subsystems are based on data of different sample sizes , accuracy , and levels of variations , making it difficult to decide if the difference between two TxCAP score is a true difference or measurement error . Therefore , whether the use of TxCAP is an effective and consistent means to measure the TxDOT roadway maintenance conditions raises concerns and needs to be evaluated . In order to achieve this objective , statistical analyses of the system were conducted in two ways : 1 ) to determine whether sufficient samples are collected for each of the subsystems , and 2 ) to determine if the scores are statistically different from each other . A case study was conducted with a dataset covering the whole state from 2008 to 2010 . The case study results show that the difference in scores between two districts are statistically significant for some of the districts and insignificant for some other districts . It is therefore recommended that TxDOT either compare the 25 districts by groups /tiers or increase the sample size of the data being collected to compare the districts as individual ones . |