Concurrency (road) - Consolidation Plans For Concurrencies

Consolidation Plans For Concurrencies

Some brief concurrencies in the past have been eliminated by reassigning the designations along the roadways. This can involve scaling back the terminus of a state highway to the end of a concurrent section. At the same time, there could be an extension of another highway designation that is used to replace the newly shortened designation with another one. For instance, US 27 in Michigan previously ran concurrently with I-69 from the Michigan–Indiana state line to the Lansing, Michigan, area. From there it turned northwards to its terminus at Grayling. In 2000, the Michigan and Indiana departments of transportation petitioned the American Association of State Highway and Transportation Officials for permission to truncate US 27 at Fort Wayne, Indiana. In 2002, Michigan removed the US 27 designation from I-69 and extended the US 127 designation from Lansing to Grayling.

Some consolidation schemes involve the use of incorporating two single-digit numbers onto one marker, as along the U.S. Route 1/9 concurrency in northern New Jersey.

Other plans to avoid concurrencies involve rerouting an older designation off a highway when a new moniker is being applied. When I-795 was applied to the US 117 freeway in North Carolina, instead of forming a concurrency, US 117 was instead returned to its original parallel alignment. There are even instances of a surface-street and freeway less than 5 miles in parallel where they both implement concurrencies; for instance, Interstate 40 is concurrent with U.S. Route 74 on the freeway part and U.S. Route 19 is concurrent with U.S. Route 23 on the surface street part in parallel between Clyde, NC and Asheville, NC. Then, U.S. Route 23 forms yet another concurrency when it diverts off the east-west surface street onto the "physically" north-south Interstate 26 to the north.

Some routes avoid concurrencies altogether by having their corridors physically cross or deviate within less than 500 feet (150 m), but the intersecting numbered routes ricochet their trajectory off the junction to avoid a concurrency. One example involves North Carolina Highway 111 and US 117 north of Goldsboro. I-80 and I-76 both switch from non-toll freeway to the Ohio Turnpike near Youngstown. Ontario Highway 403 goes northwest and diverts northeast where Ontario Highway 407 forms connector ramps as that highway curves from northeast to northwest on the same survey line; this was a civil engineering tactic that the MTO used to avoid having a cloverleaf junction at a four-way freeway crossing.