00966546

Component

https://doi.org/10.3141/1847-07

http://scholar.google.com...isar&publication_year=2003

Although the single-point interchange (SPI) has been around for approximately three decades, users do not yet have a simplified procedure to evaluate its traffic performance with a similar configuration, the tight diamond interchange (TDI). Several studies have derived general results without decisive conclusions or with partial coverage to assist the users in the selection process. Simulation modeling is used to compare operational traffic performances of isolated SPI and TDI without frontage roads. Modeling was conducted on similar geometries over a wide distribution of traffic flow conditions (101 scenarios). The 101 scenarios were run for both SPI and TDI to derive control delay, stop time, and percent stops from CORSIM. The multivariate statistical comparison of all three variables showed a combined significant difference between the two interchange types, favoring SPI. TDI created more delay, stop time, and percent stops when the left-turn off-ramp flows were very high. Regression models were derived to estimate the three measures for both SPI and TDI. The models are robust and are functions of the highest flows on the cross street and off-ramps. These models are tools that can help planners in the evaluation and selection process of these interchange configurations.

This paper appears in Transportation Research Record No. 1847, Operational Effects of Geometrics 2003.

English

p. 52-57

2003

Transportation Research Record

0309085837

Figures (9) ; References (9) ; Tables (5)

Highway operations; Multivariate analysis; Performance; Planning; Regression analysis; Single point urban interchanges; Stopped time delays; Stopping; Traffic delays; Traffic flow; Traffic models; Traffic simulation; Types of interchanges

CORSIM (Traffic simulation model)

Tight diamond interchanges

Data and Information Technology; Highways; Operations and Traffic Management; Planning and Forecasting; I73: Traffic Control

TRIS, TRB, ATRI

Dec 8 2003 12:00AM

• COMPARISON OF OPERATIONS OF SINGLE-POINT AND TIGHT URBAN DIAMOND INTERCHANGES
• COMPARISON OF THE NEW W-INTERCHANGE WITH CONVENTIONAL INTERCHANGES
• DETERMINATION OF STORAGE LENGTHS OF LEFT-TURN LANES AT UNSIGNALIZED INTERSECTIONS USING M/G2/1 QUEUING
• DEVELOPMENT OF DESIGN VEHICLES FOR HANG-UP PROBLEM
• EFFECTS ON ROAD SAFETY OF CONVERTING INTERSECTIONS TO ROUNDABOUTS: REVIEW OF EVIDENCE FROM NON-U.S. STUDIES
• OPTIMAL LOCATION OF U-TURN MEDIAN OPENINGS ON ROADWAYS
• SPEED DIFFERENTIAL AS A MEASURE TO EVALUATE THE NEED FOR RIGHT-TURN DECELERATION LANES AT UNSIGNALIZED INTERSECTIONS