01334301

Component

When volume is at the capacity level, one can find maximum flow rate over a particular time interval (e.g. 15-min) as the capacity of a bottleneck. However if the traffic volume is high but still not close to capacity conditions, some vehicles are likely to maintain large headways. For such a condition it will be shown that the above method may not return a reasonable capacity. In this paper, a new method is proposed to measure capacity that returns reasonable capacity even when traffic volume is not at capacity level. Thirteen data sets and totally about 9 hours of data collected from several work zones are available. The data sets have different traffic conditions and the proposed method was applied to the data. Based on the results of the method capacity values are suggested for each traffic condition. The suggested capacity values for sites with speed limit of 45 mph vary between 1,200 pcphpl to 1,550 pcphpl. The lower value is associated with a site with flagger, work activity and queue while the upper value was suggested for sites with no work activity and no queue. A capacity value of 1,600 pcphpl is suggested for work zones with speed limit of 55 mph, dynamic speed feedback sign, no queue and no work activity. The suggested capacity for a site with speed limit of 55 mph, short-distance work zone, no queue and no work activity is 1750 mph. A short-distance work zone is a work zone where drivers are able to see the end of the work zone when they enter the transition area.

01329018

11-3968

English

12p

2011

Transportation Research Board 90th Annual Meeting

DVD

References (11) ; Tables (2)

Field studies; Highway capacity; Traffic data; Traffic flow rate; Traffic volume; Work zone safety; Work zone traffic control

Traffic conditions

Data and Information Technology; Highways; Operations and Traffic Management; I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2011 Paper #11-3968

TRIS, TRB

Feb 17 2011 6:42PM