LEVEL OF SERVICE ANALYSIS FOR TWO- LANE, TWO-WAY FEDERAL HIGHWAY OF ETHIOPIA

This research has focused on the level of service analysis of selected two-lane, two-way Roads Segment based on prevailing field condition. The study has predicted the performance of those selected two-way two-lane roads how they perform in the future five years for projected traffic starting from 2017 to 2022 based on exhibited traffic growth trend. The analysis of Level of service for current and future five years has been performed using HCS, 2010 software. The data required as an input in HCS 2010 software were collected from field, from ERA traffic count record. The results of HCS 2010 software analysis has shown that those roads segments are operating currently at undesirable levels of service between C and E. The future five years analysis has shown that LOS fall to the undesirable level between C and E. The computed 85th percentile operating speed adopted as speed limit to compute BFFS. BFFS has been performed by adding 10 mil/h in to 85th percentile operating speed. By using BFFS that obtained from 85th percentile operating speed and by changing lane width from 3.5m to 3.66m and shoulder width from 1.5m to 3m, LOS simulation has been performed. The result obtained from this simulation shows that LOS for Addis Ababa-Sendafa, Sendafa-Addis Ababa, and Sebeta-Tulubulo roads segment has been improved and fallen in to B. However, by using BFFS value only that obtained from 85th percentile operating speed and by changing lane width from 3.5m to 3.66m and shoulder width from 1.5m to 3m, LOS for Sululta-Chancho, Chancho-Sululta, and Tulubulo-Sebeta still has been fallen in undesired level as LOS governed by both ATS and PTSF values. To improve the LOS of those roads segment, the study has assigned passing lane and simulated in to HCS 2010. LOS has been fallen in to B category by using 0.8mil for Chancho-Sululta, 0.9mil for Sululta – Chancho and 1.1 mil for Tulubulo-Sebeta roads segment. Even though the riding quality of those two-lane, two-way roads segments are in good condition, LOS decline from time to time ...