NJ Turnpike widening from 6 to 12 lanes from Exit 6 to 9 at cost of $2 billion

The New Jersey Turnpike Authority is moving ahead with detailed engineering on its largest widening project in two decades - taking 56km (35mi) of mostly 3+3 roadway to 3+3+3+3 lanes which the Turnpike calls "dual-dual" roadway.

This will extend south into central New Jersey the format providing for cars-only roadways on the inside and cars plus trucks roadways on the outsides - each as full self-contained expressway facilities with its own ramps allowing all movements at interchanges.

Standard format for the new road will be:

- four roadway pavements of 16.2m (53ft) providing three 3.65m (12ft) travel lanes, a rightside shoulder lane the same 3.65m (12ft) and a leftside offset of 1.52m (5ft),

- three medians between the four roadways of 7.9m (26ft)

- overall right of way a minimum of 91m (300ft)

The $2b project requires:

- adding twin 3 lane roadways to the outsides of the existing two roadways from IC6 at MP48 to IC8A at MP73

- third laning a 2+3+3+2 section IC8A at MP73 to IC9 at MP83

- rebuilding overbridges

- building new ramps including jumpovers and split ramps to provide separate access and egress for the parallel roadways without weave across movements

- reconstructing one toll plaza known as IC8 and expanding IC7A plaza, both as conventional lane constrained lowspeed stop-to-pay tolling

- buying extra slithers of land and adding soundwalls in places

The project will add 274 lane-km (170 lane-miles) and is calculated to meet traffic needs through 2032. Forecasts are based on employment growth in central Jersey of 32% 2005-2032 and traffic increases on the Turnpike of about 80%!

About 40 houses have to be acquired and demolished for the NJ widening.

A draft enviro impact statement is complete, public hearings are under way, and final engineering is starting. Construction is planned to begin in 2009 for completion 2013.

Lewis Berger and HNTB are engineers on the project.

The Turnpike has  a nice website produced by HNTB from which we got the illustrations:

see http://www.njturnpikewidening.com/

High end costs

Cost per lane-km of the work is $7.3m and $11.8m/lane-mile. This is high-end roadwork in quality and cost.

Compare the private sector 407ETR in Toronto which has just finished adding 132 lane-km or 82 lane-miles to its central section going from 3+3 lanes to 5+5 lanes, about half the extra lane-distance of the NJ Pike project but at less than one-tenth the cost of the NJ Pike - $175m at $1.32m/lane-km and $2.13m/lane-mile.

The Canadian widening was a planned widening into a central median, requiring less bridging, minimal new ramps, and no extra land.

Other differences are the truck proportion of traffic is small on 407ETR vs NJ Pike. And built from scratch for cashless tolling, it has no toll plaza costs.

Still that $11.8m/$2.13m lane-mile is a huge 5.5 fold difference in lane-distance costs.

see http://www.tollroadsnews.com/node/3141)

TOLLROADSnews 2007-09-24