What is the drawback of Underwood’s Exponential Model?

Traffic Stream Models topics include: Greenshield’s macroscopic steam model, greenberg’s logarithmic and underwood’s exponential models. Traffic stream models are based on assumptions and attempt to establish a better relationship between traffic parameters. They focus on relationships among speed, flow, concentration, and measurement capability.  Traffic stream models provide relationships among the three basic traffic variables under steady-state conditions: Speed, Flow, Density.  Some prominent traffic stream models include: Greenberg's logarithmic model Underwood's exponential... Show more

Traffic Stream Models topics include: Greenshield’s macroscopic steam model, greenberg’s logarithmic and underwood’s exponential models.

Traffic stream models are based on assumptions and attempt to establish a better relationship between traffic parameters. They focus on relationships among speed, flow, concentration, and measurement capability. 

Traffic stream models provide relationships among the three basic traffic variables under steady-state conditions: Speed, Flow, Density. 

Some prominent traffic stream models include:
Greenberg's logarithmic model
Underwood's exponential model
Pipe's generalized model
Multi-regime models 

The main types of traffic models are macroscopic, mesoscopic, and microscopic:
Macroscopic models: Consider the aggregate behavior of traffic flow
Microscopic models: Consider the interaction of individual vehicles 

Related:

Traffic Engineering Practice Test: Traffic Capacity

Traffic Engineering Practice Test: Fundamental Principle of Traffic Flow

Traffic Engineering Practice Test: Speed Studies

Show less