Transportation engineering

Design a northbound section of interstate that is to carry 150,000 travelers a day (excluding truck occupants). The vehicles that carry these people include; (1) personal vehicles (average occupancy of 1.2 people per car) 2-2 kip single axles, and (2) buses with 2-22 kip single axles (assume they are filled with an average of 40 passengers). 5% of all travelers go by bus (the rest go in personal vehicles). Likewise 3.6 thousand tons of goods per day are transported in standard trucks with average payload of 6 tons per truck. There are also trucks on the roadway and all trucks have 1-40 kip triple axle, 1-32 kip tandem axle, and 1-8 kip single axle. You know that the soil CBR is 6 (Use Table 4.9 to approximate Modulus of Subgrade reaction), the initial PSI is 4.5 and the TSI is 2.5. Other values to be used: All drainage coefficients = 1.0 Reliability = 90% Overall standard deviation of traffic = 0.50 Concrete Modulus of Elasticity = 5.5 million lb/in2 Concrete Modulus of Rupture = 750 lb/in2 PCC load transfer coefficient = 3.0