$(3)$

b$)$ Simulate a priority intersection to process all the major road vehicles with headways: $6,7,10,2,2,4,9,3,4,8,2,2.$ Critical gap $(H_0)$ for the minor road is $7s.$ The minor road vehicle processing rule is defined by the equation: $h_i-H_0+M-n_i**M0$; where $M$ is the vehicle move up time $(2s$ for yield sign, $4s$ for stop sign$),h_i$ is the headway of the major street vehicle and $n_i$ is the number of vehicles on the minor street.

$(4)$