摘要: |
The effects of raters' characteristics, vehicle classes, and highway classifications on panel ratings are described. Development of the present serviceability index (PSI) models as well as determination of the terminal PSI values for different highway classes in Taiwan also are investigated. Freeways and provincial highways as well as city streets were selected for use in evaluating road serviceability. A rating panel of 20 people rated the selected sections while they were in passenger cars and on buses. Pavement roughness also was measured with the Mays ride meter, and a manual distress survey was conducted to collect the pavement distress data. It is found that raters' ages did not have a significant effect on the ratings, but factors of raters' seat location on the bus, driving experience, and gender affected the ratings significantly. Another interesting finding is that raters tended to give lower ratings for freeways and provincial highways than for city streets, even if they were equally rough. Therefore, the terminal PSI of the former (2.1) was higher than that of the latter (1.8). Two PSI models that describe the relationship between panel ratings, pavement distresses, and roadway roughness are established and presented. Due to the large percentage of passengers who travel on buses within the city, a PSI model based on the ratings of city streets by a panel of raters on buses is recommended for the city system, and a PSI model developed from data for ratings of freeways and provincial highways by a panel of raters in passenger cars is recommended for highway systems. |