Evaluation of Possible Sustainable Solutions to Road Defects in Karachi

Road defects are inevitable in the infrastructure of any city but its effects on the safety of road users and overall economy vary. There are several factors which contribute towards the magnitude and frequency of such defects and how much human and financial loss they incur. Finding suitable solutions to these road defects which are cost effective as well as sustainable are necessary. This study aims to explore the various common road defects, their cause and possible sustainable solutions. Different localities in the city of Karachi were selected for estimating the average frequency and magnitude of common road defect types. It was found that on an average there were 2.8 potholes, 1.5 ditches, 1.68 speed breakers, 1.3 open manholes, and 0.16 open nullahs per kilometer in Karachi. All together they constitute about 59,436 road defects in the city of Karachi. The most hazardous of them are the open manholes which account for day to day fatal and severe injury accidents. Some of the solutions evaluated for the repair of these road defects were concrete debris, aggregate mixture (gherha), earthen backfill, and used rubber tire strips based manhole cover.