Storm water fight has Penn Pike suspend $300m of work NW of Phily, but talks resume

Pennsylvania Turnpike Commission have suspended further work on a 10km (6 mile) rebuild project and a new all electronic toll (AET) interchange on the northwest fringe of the Philadelphia area because of inability to gain acceptance of normal stormwater basins. They said in a March 24 letter that local demands for expensive poured concrete stormwater storage or dispersion technologies rather than regular stormwater dams make the project unaffordable.

Two projects are involved in the work suspension:

- Turnpike Mainline (I-76) rebuild/widening from the Valley Forge Interchange (MP326) to PA29 in Tredyffrin (MP320) estimated to cost $220m

- new all electronic toll (AET) interchange at state route 29, which presently has no connections to the Turnpike, a project at the end of the proposed rebuild/widening at milepost 320 (MP320) costing $70m

Timothy Carson acting chairman of the Commission says that since suspension of the two projects was announced four weeks ago the Turnpike had heard from many local stakeholders asking for a resumption of talks with local public officials in the hope of reaching an agreement.

"We've reopened dialog," Carson says.

At issue is the acquisition of seven local private properties including houses needed to provide land for a series of stormwater retention basins or dams.

Historic park

Much of the northside of the pike over the distance of the project is Valley Forge National Historical Park where General George Washington's army of 11k camped in the hard winter of 1777/78 and where in the spring of 1778 a German captain Baron Friedrich von Steuben, (presented to the troops as a "Prussian Lieutenant General) implemented the first standard drill of the US Army improving its tactical skills.

The historic park operated by the National park Service is out of bounds for stormwater dams.

That leaves the southside with suburban and office park development and many private properties to be acquired.

New roads are required to provide large stormwater storage whereas old roads like the original Penn Pike (built 1936 to 1950) had no stormwater management.

The MP320-MP326 rebuild is estimated to cost about $220m with conventional contemporary storm water basins - excavated earthen dams - built on acquired land.

With local officials opposed to the land acquisition the Turnpike would have to construct huge concrete storage tanks under stretches of the new roadway, adding they estimate $70m to $100m to project costs.

The rebuild involves:

- complete removal of the existing 2+2 travel lane expressway with single shoulder lanes on the right and a tight lefthand offset from a median barrier with new 3+3 travel lanes,

- four shoulder lanes and a more generous median (8m or 26ft versus the existing 3m or 10ft),

- rebuilding of three overbridges and seven underbridges,

- and new soundwalls

see sections below

Cost of 58 lane-km (36 lane-miles) of travel lane at $220m total works out at $3.8m/lane-km ($6.1m/lane-mile.)

This stretch of roadway is the most heavily trafficked 4 lane stretch of the Pennsylvania Turnpike carrying about 50k average daily traffic.

A Turnpike spokesman told us the new interchange at PA29 makes no sense without a viable plan to rebuild and widen the Turnpike mainline to Valley Forge. The extra traffic attracted by the interchange will overburden the existing 2+2 lanes.

Both projects, while separate in their permitting and contracting were suspended because they are logically connected.

The milepost 320-326 rebuild project is part of a "$2 billion total reconstruction program" initiated in 1999 under which about 100km (60 miles) of roadway have been reconstructed and 30km (18.5 miles) are presently in construction, with almost 640km (400 miles) yet to be rebuilt. Old pavement is removed totally and new grades set and foundations and drainage built for new pavement.

PA29 has a number of business and office parks along it and their employees and customers are not able to use the Turnpike at present because of their distance from any interchanges. The area also has a developed suburban population in single family houses.

Reaction

A local report says: "Members of both political parties in Chester County are decrying the Pennsylvania Turnpike Commission's recent decision to suspend work on the Route 29 slip ramp to the turnpike in Charlestown. The long-planned project was designed to decrease traffic congestion on Route 202 and nearby residential roads."

A county Commissioner Kathi Cozzone, a Democrat is quoted: "There is a lot of public support for this." Her Republican colleague, Carol Aichele also said she hoped the turnpike commission would "revisit" the suspension.

BACKGROUND: The proposed PA29 interchange is located in a 22km (14 mile) stretch of the Turnpike between interchanges at Valley Forge at MP326 in the east and Downington at MP312 to the west.

The Turnpike Commission's first AET interchange was Virginia Drive at MP340 due north of Philadelphia. This has ramps only on the northern side of the mainline to local streets, and no bridge integral to the interchange. Traffic wanting to cross over the mainline uses an existing bridge of Susquehanna Rd just a block away. Virginia Drive not being a real interchange is best described as a pair of AET ramps. Just a mile away from the full Fort Washington interchange at MP339 it basically provides shortcuts to motorists who'd otherwise go through Fort Washington IC.

Slip ramps misnomer (TERMINOLOGY)

The Turnpike Commission has been using the term "slip ramps" to describe the interchange at PA29 and other proposed all-electronic toll interchanges. In fact the interchange at PA29 is a 4 directional trumpet interchange. It has no slip ramps as commonly understood in north America at least, where slip ramps are highspeed connections between the mainline of an expressway and a frontage or collector-distributor running parallel. (see diagram at right)

The Turnpike seems to have adopted a peculiar British usage in which any ramp of any interchange (or junction as the British say) is a 'slip ramp.'

We'll stick with the conventional north American usage. Therefore it's an interchange they are proposing at PA29, and like all interchanges it has ramps, in this case four being ramps, none being slip ramps since no frontage roads are proposed.

Since there will be no cash collection it is All Electronic Tolling and hence an AET interchange or toll point.

TOLLROADSnews 2009-04-20