Birmingham AL US-280 Elevated tollway?

Birmingham AL US-280

Elevated tollway?

A major investment study with a toll option has begun for an upgrade to a major radial highway in Alabama’s largest city, Birmingham (pop 1m). US-280 is a presently a 4 to 6-lane signalled arterial, heavily congested with about 60kv/d, but because it leads directly southeast into the rapidly developing Shelby county it is expected to have to cater for 110kv/d by 2015. The study corridor is an extension of an old expressway (the Elton Stephens Expwy or US-31) that extends some 6km south out of the central business district. The US-280 project goes another 16km southeast through some of the classier new commercial and industrial parks and shopping areas of the metro area. On the way it crosses I-459, a south bypass expwy.

Blaise Carriere of Howard Needles in Baton Rouge LA is the consulting engineer in charge of the study. He says preliminary engineering work suggests a tollway could consist of split elevated 2-lane roadways made of 75m long prefabricated concrete sections with 17 pairs of ramp connections to the surface arterial underneath. Together the 10-lanes would provide capacity of 140kv/d at a cost of $325m. Options being considered are:

• express bus, carpooling and no-growth landuse policies ($6m)

• expansion of the arterial to 8-lanes signalized ($44m)

• 10 grade separations at the major crossroads and at grade signals at lesser streets ($200m)

• reconstruction of the arterial to full mwy standard with a pair of single lane frontage roads ($360m)

• a new parallel relief expwy ($360m to $600m)

• light rail ($225m)

• no-build in the northern half, major grade separations in the southern newer half of the corridor ($120m)

• elevated tollway ($325m)

A chart distributed at the first public meeting Feb 18 shows that only the expwy/frontage roads, parallel relief expwy and elevated tollway options provide adequate capacity. And the elevated tollway provides the greatest capacity and is the simplest and cheapest to build of the three adequate capacity solutions. And of course if it makes sense to investors it will be lightest on the public purse.

Carriere told us it remains to be seen if an elevated structure is acceptable to local communities on esthetic grounds. Rather little of the traffic is through traffic wanting to go the whole length of the corridor so plenty of ramps are needed. The highway would have to be equipped for fully automated tolling. Wilbur Smith is doing traffic and revenue studies. (Contact J.F.Horsley ALDoT 205 328 5820, Blaise Carriere, HNTB 504 927 8392)