Highway interchange design promises land savings

A new more compact type of highway interchange has been designed by faculty and graduates at North Carolina State University.
Calling it, a “nano-interchange,” Dr. Joseph E. Hummer, professor, and master’s graduate Meredith L. Harris, designed a freeway that saves between 10 and 30 acres of land compared to a conventional four level interchange. Construction costs and right-of-way requirements were taken into account, but the safety factors are still being studied.
The nano-interchange designs divide each freeway into two levels. The north-south freeway, for example, is split so that the southbound level is the lowest of all four levels and the northbound is the highest. Crossing, but sandwiched between these to levels are two more levels that make up the east-west freeway. With the main lines arranged in this manner, the ramps can be direct turns.”
A possible disadvantage, notes the release, is that the design involves left-hand exits and entrances, which people are not used to. However, the potential for using more compact interchanges is very evident in development countries where cities are crowded and dense.
Hummer said they would like to see the nano-interchange tried by designers and agencies.
Source: NC State News Services