If the traffic flow is saturated, vehicle headways should fluctuate around the saturation headway.
Equations (3a) and (3b) show that [DELTA]e follows a normal distribution with zero mean and 2[[sigma].sup.2.sub.e] variance, which provides a first method to test whether the vehicle headways in the time series are saturation headways.
Both calculations on lane capacity and start-up loss time rely on the discharge headway of queued vehicles.
As defined in HCM [1], headway is the time between successive vehicles as they pass a point on a lane or roadway, measured from the same point on each vehicle.
One thousand
headways are simulated and critical gap can be calculated by various methods in Table 3.
The distribution of
headways in the major stream is described by a statistical function.
In order to classify the collected
headway data, the flow scopes with the length of 100 pc/h/ln were defined for each lane and the
headways belonging to each 5-minute time interval were put into the corresponding flow scope.
Schools can book a performance by calling
Headway on (01670) 351962 or emailing HeadwayT@aol.com
There is, however, one other reason for the short
headways, and it is that drivers are incapable of estimating
headways correctly.
One is to make fast buses slow down, and the other is to make slow buses speed up, and then the
headways between buses can be equalized.
This was done because we assumed that an open roadway gave the drivers an opportunity to increase their speed, and we wished to see if drivers who tended to exceed the speed limit would exhibit
headways that were different when receiving alerts than when not receiving alerts.
To determine liability for maintaining safe
headway and to enforce safe
headways, it is necessary to first examine whether the problem lies in the drivers' inability to correctly estimate distances to vehicles ahead, or whether the drivers knowingly violate the law.