Mumbai university > civil engineering > sem 5 > transportation engineering 1

Marks: 5M

Difficulty: Difficult

Thirtieth highest hourly volume is the hourly volume that will be reached only thirty times or exceeded only 29 times in a year and all other hourly volume of the year will be less than this value.

The highway facilities designed with capacity for 30 highest hourly traffic value is assumed year is found to be satisfactory from the consideration of facility as well as the cost. This is because the cost will be much leaser when compared to the peak hourly volume and there will be congestion only during 29 hours in the year and this is considered reasonable.

Thus , the 30 highest hourly volume is generally taken as the design hourly volume for the purpose of design of the roadway facility . Instead the design hourly traffic volume may also be decide by drawing the diagram as shown in fig after carrying out traffic volume studies on the desired location of the road. The design hourly volume thus arrived at need not necessarly coincide with the 30 highest hourly volume in all the cases.