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Route 42 Bridges Over Blackwood Railroad Trail Being Removed. Large Pedestrian Tunnel Under Construction

Route 42 Bridges Over Blackwood Railroad Trail Being Removed. Large Pedestrian Tunnel Under Construction
Reading Time: 7 minutes

Earlier this year NJDOT contractors started another bridge replacement project on South Jersey’s Route 42, this one targeting the bridges over the Blackwood Railroad Trail in Gloucester Township.

The plot-twist with this project is… they are actually REMOVING these bridges and not rebuilding them as bridges! Dirt will be filled in and the roadway will be a more traditional road construction.

But how will residents use the “Blackwood Railroad Trail” that was developed on the path of the former train tracks, if there are no bridges?

Well a very large (tall and wide) pedestrian tunnel is being developed first to facilitate the continued use of the now named “Gloucester Township Health & Fitness Trail”.

The $21.3 million project which started earlier this year which will fully remove the two bridges over the trail (North and Southbound segments), has had minimal impact on drivers thus far as the initial phase is focused under the bridge to build the arch supported tunnel.

But Route 42 lane shifts and slowdowns will eventually come over the next 18-24 months!

More construction for Route 42 in South Jersey as these bridges over the Blackwood Railroad Trail will be removed, replaced with a traditional dirt supported roadway, and a pedestrian tunnel is being built underneath. (Image: 42Freeway.com)

The location is immediately North of the Black Horse Pike exits of Route 42. On the local road level, Woodland Ave Gloucester Township is the closest road.

Once completed there will be new benefits to drivers on the 42 Freeway, such as longer shoulders to decelerate when exiting the highway to the Black Horse Pike.

The project was reviewed with the community in 2018 and construction started in January of 2022 (pdf)

The full project is expected to be complete by July 2024.

This is one of a series of large road upgrade projects in the core 42Freeway area including the already replaced Rt 42 bridges over lower landing road

Scroll and read for more details!

Route 42 Bridges Over Blackwood Railroad Trail

America saw a huge development increase in it’s highway system during the 1950s and 60s, much of it driven by the Federal Highway Act of 1956.

This also triggered the development of State highways like New Jersey’s Route 42, whose modern variant from Bellmawr to Turnersville opened in 1959.

With many of those Highway Act era bridges in America now getting close to 70 years old (or older), Transportation official around the county have been looking at highway infrastructure to identify deficient segments, and any steps needed to improve or rebuild.

More construction for Route 42 in South Jersey as these bridges over the Blackwood Railroad Trail will be removed, replaced with a traditional dirt supported roadway, and a pedestrian tunnel is being built underneath. (Image: 42Freeway.com)

In the case of the “Route 42 Bridges Over Blackwood Railroad Trail”, NJDOT documents offer the following need to address:

The existing Route 42 bridges are proposed to be replaced and improved in order to remove the structural deficiencies in a manner that is most cost effective in the long term, to improve congestion and safety, and to address deficiencies in cross slopes and shoulders. In addition, the improvements include addressing deficiencies in acceleration and deceleration lanes,

NJDOT – Engineering Report for the “Route 42 Bridges Over Blackwood Railroad Trail” project

The new design for traffic purposes offers the following features:

  • Six 12-foot wide through lanes of traffic (3 in each direction)
  • upgraded auxiliary lanes and shoulders
  • A newly filled median over the new precast arch structure (more on the arch in a minute)
  • Typical roadway section will include
    • 10-foot wide outer shoulders
    • 4-foot wide inside shoulders
    • 14-foot wide & varies Northbound auxiliary lane
    • 12-foot wide Southbound auxiliary lane.
    • The new Northbound and Southbound roadways will remain separated by an approximately 54-foot wide grass median.
A portion of the Gloucester Township Health and Fitness Trail, from 2016. (Image: 42Freeway.com)

Did you catch these two comments? “Newly filled median” and “separated by an approximately 54-foot wide grass median”?! Literally the bridges will be gone and it will a dirt supported roadway segment with a traditional grass median center.

Interestingly the 2016 report calls out that the improvements would also better accommodate “a future Route 55/42/I-676 Rapid Transit Project on the NB roadway”. But don’t get excited over this as I believe the report is referring to a much earlier discussed Patco expansion project down Route 42, which was eventually moved over Conrail line right-of-ways to become the proposed Glassboro-Camden Line.

New Era Means New Plans

So with the need to rebuild clearly defined and additional requirements fully laid out, the project engineers moved on to “what do we do to replace the bridges?”

Well you must also consider that the railroad tracks existed in Blackwood before the modern version of Route 42 was developed.

So back in the 1950s when the freeway was designed and built, engineers developed this segment of Route 42 OVER the railroad tracks via two large bridges (Northbound and Southbound).

But today Railroad train usage is down considerably across the country, and in this particular section… the trains no long run!

In fact, many years ago railroad and transportation officials were so certain that railroad trains in this area were a permanent fixture of the past, the actual tracks were removed!!

Considering the additional costs of rebuilding as bridges, not to mention the ongoing maintenance costs of bridges over the decades, NJDOT decided that bridges were no longer needed for this section.

An earth supported, more standard developed roadway, would less expensive to build and fewer things to maintain.

Where We’re Going, We Don’t Need Railroads!

With the railroad tracks in that portion of Blackwood no longer in use, years ago a plan was put into place to repurpose the path of the trains.

Years ago officials decided to remove the tracks entirely, and repave with asphalt what was the original pathway of the trains. They were to be used as a pedestrian trail for walking, jogging and biking!

This process is also taking place around the country, to find new beneficial community uses for these typically very interesting passageways that were developed.

I say “interesting” most of these train routes were developed before most of the modern towns and roadways were built up around them. So today with the tracks removed, it can make for interesting passageways for the public that did not exist previously!

And in the case of the old Blackwood railroad tracks they were initially completed back in 1891!! No.. not 1991, EIGHTTEEN NINETY ONE!

Gloucester Health and Fitness Trail Tunnel

So finally we get to “The Tunnel”

It seems it was important to all involved that the pedestrian trail be kept intact, so that even after the Route 42 bridges here were removed, residents could use the trail and move past the bridges.

To accommodate this, the plans call for a large pedestrian trail tunnel.

defaultMore construction for Route 42 in South Jersey as these bridges over the Blackwood Railroad Trail will be removed, replaced with a traditional dirt supported roadway, and a pedestrian tunnel is being built underneath. (Image: 42Freeway.com)

So maybe some will be concerned by “tunnel” for a variety of public safety reasons.

But NJDOT documents describe the tunnel as:

The constructed tunnel will have a minimum vertical clearance of 17-feet as requested by PSE&G and a horizontal clearance of 22-feet for pedestrian and bicycle trail us

NJDOT Tunnel plans for the Blackwood Railroad Trail under Route 42.

Simply.. being 17 feet high minimum and 22 feet wide…. this is a very large tunnel.

If they wanted to, you could drive two tractor-trailers through something this size… SIDE BY SIDE!

Project documents also state the pedestrian tunnel will have lighting and security camera(s).

A portion of the Gloucester Township Health and Fitness Trail, from 2016. The overpass in the distance is Route 42. Those bridges are being replaced and a pedestrian tunnel developed. (Image: 42Freeway.com)

In our recent visit to the project site, construction crews are focused on building the tunnel’s thick vertical walls.

Once those vertical walls are completed, above them a massive precast arch structure will be set in place connecting to those vertical walls.

At some point earth will be filled in on the outside of those walls, and then up over top of the arch, to build the foundation for the replaced Route 42 roadway.

But of course at sometime in the mix crews need to demolish and remove the old bridge structures.

It will be interesting to see how they lay the steps out in order-of-operations! My brain sees it as a “cart before the horse” challenge of how to move traffic to other lanes to remove a bridge, when you aren’t able yet to of built up the earth to the roadway.

Eh.. I’ll talk about that more in an upcoming video!

The full project is expected to be complete by July 2024.

But the Route 42 roadwork with temporary lane shifts are still to come!