Model for Estimation Urban Transportation Supply-Demand Ratio

Table 6

Value range of the TSDR under different transport conditions.

Value range	Significance	Transport conditions
	Scarce supply	Urban transport system cannot meet the challenge of residents travel: excessively crowded rail transit and bus, severe congestion on the road net, and taxi shortage.
	Short supply	In the general case, urban transport system may meet the challenge of residents travel. However, when a sudden event (even a small perturbation) or bad weather is encountered, rail transit will be crowded, many roads will become jammed, and buses will be delayed. In other words, the system has weak ability to withstand disturbance.
	Supply-demand balance	In most situations, urban transport systems can meet the challenge of residents travel and have self-adjustment ability. When a sudden event or bad weather is encountered, some roads will become jammed, and the number of rail and bus passengers will increase. These disturbances will often be quelled in short times without the interposition of managers.
	Excess supply	Under any circumstances the urban transport system can meet the challenge of residents travel.