Interchanges are a particularly important focus in transportation because of the high level of interacting cross-traffic. Often, traditional diamond interchanges are limited in their ability to provide adequate safety and operational needs. Alternative interchanges are a common solution that involve using innovative designs which work well with specific site characteristics. Because there are often many alternative designs to consider and because it can be time-consuming to model and evaluate each alternative, there is a need to expedite the process using a designated screening approach and evaluation. This thesis contains an interchange study for a corridor located in Columbia, Missouri that uses a screening process which incorporates analytical and simulation tools. Several interchanges are analyzed including: diamond, single point urban (SPUI), partial cloverleaf, diverging diamond interchange (DDI), displaced left turn (DLT), roundabout, and an innovative displaced left roundabout (DLR). The results of operational analysis show that: the DDI performs the best on the interchange for high demand; the DLR performs best for the interchange only at low demand; the current design is sufficient with the given growth volume, so an alternative is not warranted. One contribution of this thesis is the development of a systematic procedure that first screens for promising designs and then conducts an extensive simulation analysis to compare their performance.

Signalized urban interchanges are frequently used as junctions between freeways and local arterials to date. In recent years, many new interchange or intersection designs like Diverging Diamond Interchange (DDI) and Continuous-flow Intersection (CFI) have emerged across the world. However, most of the interchanges are still using conventional urban interchange designs. Among new designs, Single Point Urban Interchange (SPUI) and Tight Diamond Interchange (TDI) are the most popular. Comparison and evaluation of the safety and operation of interchanges are important in transportation engineering to choose the most appropriate option for a location. Recently, many research have been devoted to the standard TDI and SPUI. Most of them consistently prove that the SPUI outperforms TDI in operation efficiency, but few research have compared the SPUI with frontage road (SPUI-F) with TDI. This research aims to fill this gap. With this motivation, there was a real case which could be used as testing the operational efficiency between the TDI and SPUI-F. The Nevada Department of Transportation (NDOT) switched the TDI, which was located at I-580/Plumb Ln, to SPUI-F in 2003. Since this interchange has experienced TDI and SPUI-F, the Measures of Effectiveness (MOEs) for each of them can be compared. To perform this comparison, layouts of both interchanges were modeled in VISSIM. The models were calibrated using the existing volume. Several volume scenario groups were designed for testing the operational efficiency of both options. Three MOEs, including average delay, average speed and average queue length, were selected to show the operational efficiency. The results revealed that the TDI is more efficient in comparison to the SPUI-F. However, TDI might not satisfy the driver’s expectation because of the stopping between the two signals, for which SPUI-F does not have such a problem.

The main focus of this study is congestion, primarily that occurring on freeway corridors in metropolitan areas. Lack of coordination in the operation of various components of the system is often a major source of inefficiency, resulting in greater delays to motorists than what might be achievable with the existing physical infrastructure. The main objective of the study is to improve corridor network management by coordinating the various control elements in a freeway corridor, for both recurrent and nonrecurrent congestion situations.

Guidebook on designing freeways to promote healthy communities & safer streets.