Traffic Capacity Calculation for Urban Underground Interchange

Abstract:

The traffic capacity model based on expected headway time was established. According to the characteristics of urban underground interchange， the traffic capacity of main road， ramp section， merge area and diverge area in urban underground interchange was calculated， and the recommended values were given. Finally， the accuracy of the model was verified by the measured data. Study results show that， the traffic capacity of each underground interchange is reduced compared with that of ground interchange. The main road is reduced by 8%?11% （near 10% on high-speed section）， the ramp section is reduced by 14%， the ramp merge area is reduced by 10%， and the ramp diverge area is reduced by 11%.

Key words:traffic capacity;urban underground interchange;headway time;main road;ramp section;ramp merge area;ramp diverge area