Traffic Threshold for Upgrading Low Volume Roads Considering Different Maintenance Strategies

Abstract

The transport network is considered as the backbone of a society. The low volume roads in rural areas connect the people to their market and administrative centers. Upgrading and maintenance activities of these roads for all weather operation need huge resources. A proper economic decision tool is required for allocation of the scare funds by prioritizing of roads for upgrading and maintenance. The study is focused on finding the effects of maintenance activities on determining the threshold for upgrading low volume roads. During the economic analysis, HDM-4 is used as the tool to calculate the Net Present Value of a project alternative. The Net Present Value of a project alternative is the difference between the Present Value of Total Transportation Cost of base alternative and the project alternative. The traffic volume corresponding to the Zero Net Present Value gives the threshold value of the traffic volume for upgrading the road from base alternative to project alternative. The contribution of road user cost in total transportation cost is about 86%. The traffic threshold (ADT) for upgrading the earthen road to gravel road, DBST road and asphalt road is 47, 73 and 88 respectively for Ideal Maintenance Scenario and 45, 66 and 85 for Minimal Maintenance Scenario. Similarly, traffic threshold (ADT) for upgrading the gravel road to DBST road and asphalt road is 104 and 128 respectively for Ideal Maintenance Scenario and 76 and 102 for Minimal Maintenance Scenario. If proper maintenance is ensured, the threshold of upgrading road will increase. The observed value of AADT at which the upgrading of low volume road are being carried out and the theoretical AADT derived in the research are statistically indifferent.