Traffic Engineering

Use the fundamental relation q = kv linking flow, density and speed, and the Greenshields linear model to show capacity occurs at half the free speed and half the jam density.

Match the intersection type to the traffic volume — uncontrolled/priority for low flows, rotary for moderate balanced flows, signals for high flows — and design channelization and turning lanes to separate and organise movements.

Compute the critical flow ratios for each phase, sum them to Y, find the Webster optimum cycle time C_o = (1.5L + 5)/(1 − Y), and split the available green in proportion to the phase flow ratios.

Measure parking accumulation, turnover and duration from field surveys, express usage as the parking index, and estimate demand from the peak accumulation to size on-street or off-street facilities.

Apply the four-step model — trip generation, trip distribution, modal split and traffic assignment — using survey-based O-D data and PCU-based capacities to forecast and plan urban travel.