Capacity Estimation Model for Signalized Intersections under the Impact of Access Point

Area of Science:

• Transportation Engineering
• Traffic Flow Theory

Background:

• The Highway Capacity Manual 2010 lacks factors for access point influence on signalized intersection capacity.
• Access points near intersections can alter traffic dynamics and capacity.

Purpose of the Study:

• To develop a theoretical model estimating lane group capacity at signalized intersections considering access point effects.
• To analyze the impact of access point location (upstream/downstream) and traffic flow types on intersection capacity.

Main Methods:

• Development of a theoretical capacity model for signalized intersections with integrated access points.
• Validation of the model using VISSIM traffic simulation software.
• Extensive numerical analysis to assess various scenarios and traffic flow types.

Main Results:

• Access points significantly impact signalized intersection lane group capacity.
• Capacity shows an inverse correlation with the number of major street lanes and the distance to the access point.
• Right-turning traffic from the major street (flow 1), left-turning traffic from the access point (flow 4), and left-turning traffic from the major street (flow 5) have the most substantial effects.

Conclusions:

• A novel model effectively estimates lane group capacity considering access point interference.
• Practitioners can use this model and provided guidance to mitigate negative impacts of access points on intersection capacity.