Sub-problem 5a: Existing Analysis of 10-Mile Segment of U.S. 95

What other factors should be considered? The service measures for a two-lane highway are dependent on the classification of the facility. Two-lane highways are categorized primarily on the purpose they serve in the transportation system. Class I highways are facilities where speed is an important determinant of the quality of service—motorists traveling on these facilities have an expectation and desire to travel at relatively high speeds. For Class II highways, speed is not an important determinant of the quality of service, and drivers are affected primarily by the amount of time they spend following other vehicles. The service measures that define LOS for Class I facilities include both percent time following and speed. For Class II facilities, LOS is defined solely in terms of percent time spent following.

What measure should be used to determine the performance of the facility? Since U.S. 95 is currently a Class I facility, we will focus on travel speed and percent time following.

Application of the HCM methodology indicates that the average travel speed is 52.4 mph, it takes 11.5 minutes to traverse the total 10-mile segment, and the percent time spent following is 55.7%. This translates into a level-of-service "C".