NC Garden Parkway slimmed down, cost cut $1280m to $928m to enhance feasibility

North Carolina Turnpike Authority (NCTA) have slimmed down their planned Garden Parkway on the westside of the Charlotte NC metro area to reduce its costs and make it fly financially. What was a $1280m project early 2009 has a year later been cut by 27% to $928m. Construction cost is dropped 35% from $1021m to $662m and right of way cost 7% from $191m to $179m.

Biggest saving - $152m - comes from trimming  from 3+3 lanes to 2+2 lanes the major east-west portion of the roadway, some 24km or 15 miles I-485 to US321.

3rd lanes can be added in the future when traffic warrants.

The far western end US321 heading north to I-85 will be a single 2-lane roadway initially, saving $64m.

Other savings come from reducing median width ($57m), reducing earthwork ($27m), eliminating one interchange ($14m) and narrowing shoulder on bridges ($14m). 

Interchanges have been redesigned to simplify them and fit in a tighter right of way.

Cut and fill and landscaping costs will be trimmed by having the parkway follow the natural topography more closely with somewhat more horizontal wander and vertical dip and climb.

This has the additional benefit, the Authority says, of making it more a true 'parkway' and reducing visual impact, maintaining more of the rural character.

Earlier they considered leaving out  completely the 11km (7 mile) western segment US321 north-south to I-85 from the first build.

But this generated some local fears of traffic dumped on local roads.

So as a compromise one of the two planned 2-lane roadways will be built  - a so-called super-2 format.

A fighting chance

The 27% drop in initial capital commitment gives the project a fighting chance to proceed, says David Joyner, executive director, but there are still hurdles to jump. The investment grade forecasts will need to come close to the preliminary traffic and revenue projections, it will need BBB investment grade rating, a TIFIA loan must be approved, and NCDOT guarantee operating costs.

And of course the bonds have to be sold.

Schedule

Current schedule is to finalize federal permitting (Final EIS) June, conclude an investment grade traffic and revenue study, a final plan of finance, and get a record of decision by October, do a financial close Feb 2011, award contracts March next year, with a view to opening the road end-2014.

The procurement will be via a single design-build contract with a highest value fixed price based on the financial plan.

All electronic tolling

The road will have all-electronic toll collection using transponder/readers and cameras to identify vehicles without a transponder - no cash to be collected.

BACKGROUND: Garden Parkway proceeds west from I-485 near the southwest corner of Charlotte Douglas Internat Airport  and heads generally west for about 24m (15mi) when it turns north to continue about another 11km (7 miles) ending in a T-junction with I-85.

It therefore serves as a peripheral highway around the western and southern fringes of Gastonia and provides a new radial route to the airport and central Charlotte from the west.

The project is located mostly within Gaston County and was intiially known as the Gaston East-West Connector. I-485 is U-plan two-third belt route.

Segments of I-85 between Gastonia and Charlotte run 125k to 130k veh/day and have been categorized as LOS-F. The Garden Parkway should provide relief to that congestion on I-85.

COMMENT: West Virginia Turnpike was built originally as a so-called super-2 OR 1+1 lanes. The Pennsylvania Turnpike's original tunnels all involved a single lane each direction. This design is difficult to operate because of driver frustration being caught behind a 'slug' (slow vehicle.) So the design tends to generate illegal overtaking and occasional nasty head-on collisions.

You build what you can build - at least you do outside a Washington DC world of infinite debt-based 'stimulus' spending.

But 1+1 lanes for the western segment is a temporary expedient. The Turnpike will probably need to give high priority to the second separate roadway US321 to I-85 to achieve the far better 2+2 lanes for the Parkway's full length as soon as possible.

MORE: this report draws heavily on a NCTA presentation:

http://www.ncturnpike.org/pdf/Garden%20Parkway%2002-25-2010.pdf

TOLLROADSnews 2010-03-01