LOUISVILLE KY/IN:Spaghetti Junction - Tolling an Interchange?

Louisville Kentucky could be the first place to impose tolls to finance reconstruction of a complex interchange (IC). Spaghetti Junction, as they call it, is a 5-legged sausage-shaped IC, located on the waterfront immediately northeast of the Louisville central business district (CBD). It handles the switching of traffic of east-west I-64, the I-71 northeast radial, the north-south I-65 and its Kennedy Bridge over the Ohio river, as well as CBD-ramps.

Studies of the Ohio River crossing problem in Louisville found that a complete rebuild of Spaghetti Junction is at least as important as new bridges, and consultants have suggested tolls on the IC-ramps of the Spaghetti as one way to finance reconstruction. About 250k veh/day or a tenth of all the trips in the Louisville metro area go through Spaghetti Junction compared to 110k veh/day on the Kennedy bridge which is the major link between the Kentucky part and the Indiana part of the bi-state metro area on the north side of the Ohio River.

Two new toll bridges

Plans are to twin the existing I-65 Kennedy bridge downtown to provide 2x5 or 2x6 lanes (the existing bridge is 7 narrow lanes without proper shoulders), and to build a new East End bridge 12km upstream to close a missing gap in I-265 over the Ohio R. This will be built with a 2x3 lanes deck but is planned to be striped and have approach roads paved to 2x2-lanes to start with. I-265 will then provide a northern peripheral road and will enhance local mobility and improve access to a large new industrial park on the IN side.

Traffic studies and modeling done for an Ohio River Major Investment Study (MIS) completed last year showed that traffic problems in the Louisville area (pop 1.0m) could only be dealt with by building the two new bridges and rebuilding the Spaghetti Junction IC. Each seems likely to cost in the region $160m to $250m with the three projects costs totaling $500m to $700m.

The MIS conducted by JHK (now TransCore) for the local MPO Kentuckiana Planning & Development Agency (KIPDA) examined different combinations of improvements looking at three different bridge proposals (1) Downtown Kennedy (2) a midway I-264/I-265 bridge and (3) the East End I-265. bridge. The studies found that weaving problems and narrow ramps on the Spaghetti Junction were the most serious cause of area congestion and the current source of problems on the Kennedy bridge. Many sections of the Spaghetti operate for hours at LOS E and F. But the MIS found the Kennedy bridge is close to capacity too, so fixing the Spaghetti alone won’t be sufficient. Soon after 2000 the Kennedy bridge will need more capacity than its 7-lanes currently provide. Meanwhile there is the problem that breakdowns or other incidents have protracted effects on traffic because of the lack of shoulders to store wrecks.

The consultants suggest a steel truss girder design closely mimicking the present Kennedy.

A midway bridge was ruled out because it created a new spaghetti problem — the KY approach taking off too close to the I-71/I-264 IC, or else it went right over the top of a long island in the river which is something of a wildlife refuge. The study suggested a I-265 East End bridge would work, and there is an alignment that minimizes impacts, but this bridge is too far away from the center to provide much relief downtown. It found that improvements were needed to the Kennedy Brg/Spaghetti Jcn as well.

Safety improvement, time savings and lower vehicle operating costs discounted to present value were worth twice the cost of the three improvements, a better return than any other combination.

The Kentucky area is heavily involved in warehousing, distribution, air express and trucking operations. Fully an eighth of the traffic on major arteries consists of heavy trucks with over 30k/day passing through Spaghetti Junction alone. Half truck traffic is internal to the region, the other half being external. Enhanced road capacity is strongly supported in the region as essential to its continued economic vitality, though there is some serious opposition to the proposed East End Bridge (I-265) from the rich people living in this pretty area.

The MIS document assumes a mix of funding and runs several toll bridge scenarios including one in which Spaghetti Junction is tolled. Tolling the bridges alone causes suybstantial diversions of traffic to two untolled bridges, one of which, the Clark Bridge on US-31, was originally a toll bridge. One of the historic buildings to be preserved is the old Toll House.

Parsons Transp Group has just won a $22m contract with Kentucky DOT to manage detailed alignment review, public consultation, design work and environmental permitting for the three projects. HNTB has done a preliminary design for the Spaghetti Junction rebuild, which is the most difficult of the three since traffic has to be maintained through the area.

Officials there think there will almost certainly be tolls needed to support bond financing of the projects. The MIS makes no recommendations on tolling, but the strategic position of the Spaghetti Junction, and its need for major funding, makes it a logical toll point — using highway speed electronic tollong and imaging. If tolls are only placed on the Kennedy bridge, the MIS numbers suggested, there would be major traffic diversions to the US-31/Charles bridge and the I-64/Minton bridge. Spaghetti Junction tolls would intercept much of the traffic headed for those crossings. (Contacts: David Burton KIPDA 502 266 6084 kipda@iglou.com, John Clements Parsons Transp Group 502 253 9271 hjclements@aol.com)