The project includes three parts, freeway mainline section, freeway weaving and freeway merging.
Because of the interactions of the multi-lane freeway mainline, upstream, downstream, the diversity of environmental conditions, as well as the complexity of geometric configuration, speed-change lanes of the multi-lane freeway interchange present greatest safety and operational challenges for drivers.
This paper addresses a modeling approach to analyzing an integrated system that includes freeway mainlines, ramp metering, and an upstream signalized diamond interchange.
The database also stores the device working state, data validity and timing record, etc. Open image in new window Fig. 1 Locations of the loop detectors on the mainline of G60 Freeway in Shanghai.
The test area in this study is a part of mainline on the G60 Freeway in Shanghai, China.
At this location, a high volume of traffic (~1000 veh/hr) entering the already congested mainline results in reduced freeway speeds, queues, and an upstream moving shockwave that penetrates much of the section.
The study area is the entire length of the freeway, i.e. 70 km including the mainline and the Imittos Ring Road, twenty eight interchanges, four toll plazas (in the mainline) and access roads to the (two) rest areas.
This study presents a generalized model for estimating the dynamic freeway O D distribution, based on measurable time series of mainline and ramp flows, and estimated travel time distributions.
Ramp meters are installed to control the rate of vehicles moving into to the mainline traffic; thus, they prevent the critical volume of a freeway in order to control the demand and, moreover, break the platoon of vehicles entering the freeway upstream of the signal to decrease the weaving phenomenon at the merge area.
This freeway segment features a posted speed limit of 100 km/hr, has 3 to 4 mainline lanes, and experiences a directional AADT of about 70,000 vehicles.
The results indicated that the capacity value would grow with the increase of the acceleration length and mainline design speed, and the capacity values for on-ramp junctions would approach basic freeway segments capacity values while the acceleration lengths beyond 400 meters.
