Capping I-95 in Philly

[jeffandnicole]

In regards to the long-discussed plans to cover I-95 in Philly near where it's already covered, the Philly Inquirer has a sort-of update, stating that construction may be 2 years away (optimistic in my book), and there will be forums and public meetings to gather input.  Also, notable in the story, it appears that the current plan is to build all new structures, and remove the current caps.

https://www.inquirer.com/news/i95-park-cap-delaware-river-curious-philly-20190624.html

https://www.delawareriverwaterfront.com/planning/projects3/penn-s-landing/engineering

[kevinb1994]

In regards to the long-discussed plans to cover I-95 in Philly near where it's already covered, the Philly Inquirer has a sort-of update, stating that construction may be 2 years away (optimistic in my book), and there will be forums and public meetings to gather input.  Also, notable in the story, it appears that the current plan is to build all new structures, and remove the current caps.

https://www.inquirer.com/news/i95-park-cap-delaware-river-curious-philly-20190624.html

https://www.delawareriverwaterfront.com/planning/projects3/penn-s-landing/engineering

Couldn't they add more caps around the existing caps? Or is that simply not feasible due to the age of the existing caps?

[jeffandnicole]

In regards to the long-discussed plans to cover I-95 in Philly near where it's already covered, the Philly Inquirer has a sort-of update, stating that construction may be 2 years away (optimistic in my book), and there will be forums and public meetings to gather input.  Also, notable in the story, it appears that the current plan is to build all new structures, and remove the current caps.

https://www.inquirer.com/news/i95-park-cap-delaware-river-curious-philly-20190624.html

https://www.delawareriverwaterfront.com/planning/projects3/penn-s-landing/engineering

Couldn't they add more caps around the existing caps? Or is that simply not feasible due to the age of the existing caps?

Per the Delaware River Waterfront story:

To know whether we could incorporate the existing I-95 caps into the new plan or if the project would be best served by constructing all new structures, the team performed visual assessments of all structures in the Penn's Landing study area using PennDOT criteria. Based on the evaluation of the structures' current conditions and estimated lifespan as well as the desire to reduce the "humps"  in the Chestnut and Walnut Street bridges to achieve an improved line of sight to the Delaware River, the design team determined that removing all existing structures and building new would be the best and most efficient course of action. While there may be cost savings in the short term by attaching new structure to the existing cap and bridges, upcoming necessary repair and replacement of the structures would cause complications. Constructing all new structures now makes the most sense.

[PHLBOS]

^^Not to mention that the current caps are now either pushing or just over 40 years old.  When such were originally designed (by Ammann-Whitney); it was probably assumed that the cap extension would've come sooner (10 years(?)) rather than much later.

Either way as long as the finished product does not reduce the capacity (i.e. lanes) of I-95 in any way, shape or form; I'm in favor of the project. 

Ultimately, the new cap will mean that lower-profile signs (similar to ones used in Boston's Big Dig) along the I-95 mainline inside the covered area will be used rather than the current large diagrammatic signs.  Such could prove a challenge for the Exit 22 signage (I-676/US 30/Callowhill St.) since the current signs have a lot of information on them.

[kevinb1994]

In regards to the long-discussed plans to cover I-95 in Philly near where it's already covered, the Philly Inquirer has a sort-of update, stating that construction may be 2 years away (optimistic in my book), and there will be forums and public meetings to gather input.  Also, notable in the story, it appears that the current plan is to build all new structures, and remove the current caps.

https://www.inquirer.com/news/i95-park-cap-delaware-river-curious-philly-20190624.html

https://www.delawareriverwaterfront.com/planning/projects3/penn-s-landing/engineering

Couldn't they add more caps around the existing caps? Or is that simply not feasible due to the age of the existing caps?

Per the Delaware River Waterfront story:

To know whether we could incorporate the existing I-95 caps into the new plan or if the project would be best served by constructing all new structures, the team performed visual assessments of all structures in the Penn's Landing study area using PennDOT criteria. Based on the evaluation of the structures' current conditions and estimated lifespan as well as the desire to reduce the "humps"  in the Chestnut and Walnut Street bridges to achieve an improved line of sight to the Delaware River, the design team determined that removing all existing structures and building new would be the best and most efficient course of action. While there may be cost savings in the short term by attaching new structure to the existing cap and bridges, upcoming necessary repair and replacement of the structures would cause complications. Constructing all new structures now makes the most sense.

Shoot, I forgot about those bridge humps. Makes a little more sense to me now.

[kevinb1994]

^^Not to mention that the current caps are now either pushing or just over 40 years old.  When such were originally designed (by Ammann-Whitney); it was probably assumed that the cap extension would've come sooner (10 years(?)) rather than much later.

Either way as long as the finished product does not reduce the capacity (i.e. lanes) of I-95 in any way, shape or form; I'm in favor of the project. 

Ultimately, the new cap will mean that lower-profile signs (similar to ones used in Boston's Big Dig) along the I-95 mainline inside the covered area will be used rather than the current large diagrammatic signs.  Such could prove a challenge for the Exit 22 signage (I-676/US 30/Callowhill St.) since the current signs have a lot of information on them.

My thoughts exactly.

[roadman]

^^Not to mention that the current caps are now either pushing or just over 40 years old.  When such were originally designed (by Ammann-Whitney); it was probably assumed that the cap extension would've come sooner (10 years(?)) rather than much later.

Either way as long as the finished product does not reduce the capacity (i.e. lanes) of I-95 in any way, shape or form; I'm in favor of the project. 

Ultimately, the new cap will mean that lower-profile signs (similar to ones used in Boston's Big Dig) along the I-95 mainline inside the covered area will be used rather than the current large diagrammatic signs.  Such could prove a challenge for the Exit 22 signage (I-676/US 30/Callowhill St.) since the current signs have a lot of information on them.

My thoughts exactly.

Question.  Does I-95 through Philly currently have a hazmat restriction because of the capping.  If not, would one be required if the capping were extended?

[Roadsguy]

^^Not to mention that the current caps are now either pushing or just over 40 years old.  When such were originally designed (by Ammann-Whitney); it was probably assumed that the cap extension would've come sooner (10 years(?)) rather than much later.

Either way as long as the finished product does not reduce the capacity (i.e. lanes) of I-95 in any way, shape or form; I'm in favor of the project. 

Ultimately, the new cap will mean that lower-profile signs (similar to ones used in Boston's Big Dig) along the I-95 mainline inside the covered area will be used rather than the current large diagrammatic signs.  Such could prove a challenge for the Exit 22 signage (I-676/US 30/Callowhill St.) since the current signs have a lot of information on them.

My thoughts exactly.

Hopefully they do a better job than the signs on the inbound Fort Pitt Bridge. Maybe they could experiment with some tight APLs for the northbound I-676/Vine Street Expressway exit.

If anything, capacity should be expanded through the various Columbus Blvd. ramps to the older eight-lane section of viaduct, but that would probably be prohibitively expensive without greatly reducing the shoulders.

[jeffandnicole]

^^Not to mention that the current caps are now either pushing or just over 40 years old.  When such were originally designed (by Ammann-Whitney); it was probably assumed that the cap extension would've come sooner (10 years(?)) rather than much later.

Either way as long as the finished product does not reduce the capacity (i.e. lanes) of I-95 in any way, shape or form; I'm in favor of the project. 

Ultimately, the new cap will mean that lower-profile signs (similar to ones used in Boston's Big Dig) along the I-95 mainline inside the covered area will be used rather than the current large diagrammatic signs.  Such could prove a challenge for the Exit 22 signage (I-676/US 30/Callowhill St.) since the current signs have a lot of information on them.

My thoughts exactly.

Question.  Does I-95 through Philly currently have a hazmat restriction because of the capping.  If not, would one be required if the capping were extended?

No.

Probably not. It won't be that long overall, and they can install equipment that makes it safe for hazmat vehicles.

[Gnutella]

Capping urban Interstates is the best thing to do. Even the central business districts need a fast way in and out, or through. The idea to remove I-95 past Center City Philadelphia was nonsense.

Speaking of capping urban Interstates, does anybody else think that I-76 across South Philadelphia would be a good candidate for a six-lane cut-and-cover? As it exists right now, it's four lanes, functionally obsolete, and at or slightly above neighborhood grade.

[roadman]

^^Not to mention that the current caps are now either pushing or just over 40 years old.  When such were originally designed (by Ammann-Whitney); it was probably assumed that the cap extension would've come sooner (10 years(?)) rather than much later.

Either way as long as the finished product does not reduce the capacity (i.e. lanes) of I-95 in any way, shape or form; I'm in favor of the project. 

Ultimately, the new cap will mean that lower-profile signs (similar to ones used in Boston's Big Dig) along the I-95 mainline inside the covered area will be used rather than the current large diagrammatic signs.  Such could prove a challenge for the Exit 22 signage (I-676/US 30/Callowhill St.) since the current signs have a lot of information on them.

My thoughts exactly.

Question.  Does I-95 through Philly currently have a hazmat restriction because of the capping.  If not, would one be required if the capping were extended?

No.

Probably not. It won't be that long overall, and they can install equipment that makes it safe for hazmat vehicles.

Such equipment (foam suppression, retention tanks) was proposed for the Big Dig in Boston, and was actually installed in the tunnel under City Square in Charlestown.  However, two days before the City Square tunnel was opened to traffic, the Boston Fire Department objected to routing hazmat through that tunnel.  So similar equipment was never installed in the O'Neill or Fort Point Channel tunnels.

[jeffandnicole]

^^Not to mention that the current caps are now either pushing or just over 40 years old.  When such were originally designed (by Ammann-Whitney); it was probably assumed that the cap extension would've come sooner (10 years(?)) rather than much later.

Either way as long as the finished product does not reduce the capacity (i.e. lanes) of I-95 in any way, shape or form; I'm in favor of the project. 

Ultimately, the new cap will mean that lower-profile signs (similar to ones used in Boston's Big Dig) along the I-95 mainline inside the covered area will be used rather than the current large diagrammatic signs.  Such could prove a challenge for the Exit 22 signage (I-676/US 30/Callowhill St.) since the current signs have a lot of information on them.

My thoughts exactly.

Question.  Does I-95 through Philly currently have a hazmat restriction because of the capping.  If not, would one be required if the capping were extended?

No.

Probably not. It won't be that long overall, and they can install equipment that makes it safe for hazmat vehicles.

Such equipment (foam suppression, retention tanks) was proposed for the Big Dig in Boston, and was actually installed in the tunnel under City Square in Charlestown.  However, two days before the City Square tunnel was opened to traffic, the Boston Fire Department objected to routing hazmat through that tunnel.  So similar equipment was never installed in the O'Neill or Fort Point Channel tunnels.

Looking at the maps, from what I can see the capped portion of the highway will be about 600 feet long.

Over in NJ, they are building two 'tunnels' as part of the 295/76/42 project.  The current tunnel is about 500' long and other than a higher-than-normal clearance, there's no ventilation or other unusual features.  The other tunnel to be built will be about 600' long, and will at least have water pumps as the tunnel will be below the water table level.  Not sure if it'll include ventilation equipment as well.

[kevinb1994]

Capping urban Interstates is the best thing to do. Even the central business districts need a fast way in and out, or through. The idea to remove I-95 past Center City Philadelphia was nonsense.

Speaking of capping urban Interstates, does anybody else think that I-76 across South Philadelphia would be a good candidate for a six-lane cut-and-cover? As it exists right now, it's four lanes, functionally obsolete, and at or slightly above neighborhood grade.

I agree.

I don't know, but maybe they should look at the riverfront section(s) of the Surekill before any other section of Philly's I-76.

[PHLBOS]

Capping urban Interstates is the best thing to do. Even the central business districts need a fast way in and out, or through. The idea to remove I-95 past Center City Philadelphia was nonsense.

Speaking of capping urban Interstates, does anybody else think that I-76 across South Philadelphia would be a good candidate for a six-lane cut-and-cover? As it exists right now, it's four lanes, functionally obsolete, and at or slightly above neighborhood grade.

I agree.

I don't know, but maybe they should look at the riverfront section(s) of the Surekill before any other section of Philly's I-76.

Many of the riverfront sections (I'm assuming you're referring to the stretch above I-676 & 30th St. Station) are wider than 4 lanes.  From there, I-76 doesn't drop back to 4-lanes again until beyond the City Ave. (US 1 South) interchange where it leaves the City of Philadelphia.

Widening/converting the South Philadelphia stretch into a 6-lane cut-and-cover has some merit but the stretch between Grays Ferry Ave. and I-676 IMHO needs to be addressed first but is much more of a challenge due to its close proximity to 30th St. Station & its related railroad tracks as well as the bridge crossing the Schuylkill River between Grays Ferry & University Ave.

[kevinb1994]

Capping urban Interstates is the best thing to do. Even the central business districts need a fast way in and out, or through. The idea to remove I-95 past Center City Philadelphia was nonsense.

Speaking of capping urban Interstates, does anybody else think that I-76 across South Philadelphia would be a good candidate for a six-lane cut-and-cover? As it exists right now, it's four lanes, functionally obsolete, and at or slightly above neighborhood grade.

I agree.

I don't know, but maybe they should look at the riverfront section(s) of the Surekill before any other section of Philly's I-76.

Many of the riverfront sections (I'm assuming you're referring to the stretch above I-676 & 30th St. Station) are wider than 4 lanes.  From there, I-76 doesn't drop back to 4-lanes again until beyond the City Ave. (US 1 South) interchange where it leaves the City of Philadelphia.

Widening/converting the South Philadelphia stretch into a 6-lane cut-and-cover has some merit but the stretch between Grays Ferry Ave. and I-676 IMHO needs to be addressed first but is much more of a challenge due to its close proximity to 30th St. Station & its related railroad tracks as well as the bridge crossing the Schuylkill River between Grays Ferry & University Ave.

Yes, but I was also referring to the riverfront section(s) beyond City Ave, which is directly across from the Roxborough-Manayunk area of NW Philly.

[Beltway]

Many of the riverfront sections (I'm assuming you're referring to the stretch above I-676 & 30th St. Station) are wider than 4 lanes.  From there, I-76 doesn't drop back to 4-lanes again until beyond the City Ave. (US 1 South) interchange where it leaves the City of Philadelphia.
Widening/converting the South Philadelphia stretch into a 6-lane cut-and-cover has some merit but the stretch between Grays Ferry Ave. and I-676 IMHO needs to be addressed first but is much more of a challenge due to its close proximity to 30th St. Station & its related railroad tracks as well as the bridge crossing the Schuylkill River between Grays Ferry & University Ave.

It needs 8 lanes thru the city, based on traffic volumes of 120,000 to 140,000 AADT.

[Chris19001]

Many of the riverfront sections (I'm assuming you're referring to the stretch above I-676 & 30th St. Station) are wider than 4 lanes.  From there, I-76 doesn't drop back to 4-lanes again until beyond the City Ave. (US 1 South) interchange where it leaves the City of Philadelphia.
Widening/converting the South Philadelphia stretch into a 6-lane cut-and-cover has some merit but the stretch between Grays Ferry Ave. and I-676 IMHO needs to be addressed first but is much more of a challenge due to its close proximity to 30th St. Station & its related railroad tracks as well as the bridge crossing the Schuylkill River between Grays Ferry & University Ave.

It needs 8 lanes thru the city, based on traffic volumes of 120,000 to 140,000 AADT.

My thoughts exactly.

The only way you'd see 8 lanes or capping around City Ave-Belmont is if the expressway was stacked onto itself.  When last discussed, that plan got nowhere fast and would likely just be another study for the politically connected engineers to compile and have collect dust.

[Alps]

It wouldn't need 8 lanes if the freeway network was developed more according to plan.

[Beltway]

It wouldn't need 8 lanes if the freeway network was developed more according to plan.

That is true but it is the one east-west urban freeway (actually northwest to southeast but still about perpendicular to the I-95 corridor) thru Philadelphia.

There are some obvious engineering obstacles (mainly the area along 30th Street Station, how to get that many lanes thru there without filling in part of the Surekill River) but a plan needs to be developed.

[jeffandnicole]

It wouldn't need 8 lanes if the freeway network was developed more according to plan.

That is true but it is the one east-west urban freeway (actually northwest to southeast but still about perpendicular to the I-95 corridor) thru Philadelphia.

There are some obvious engineering obstacles (mainly the area along 30th Street Station, how to get that many lanes thru there without filling in part of the Surekill River) but a plan needs to be developed.

Basically, you would need to send one direction up and over the other direction, as well as over the surface streets.  But no one will like to triple deck this highway and block the views of the buildings in the area.

[Beltway]

There are some obvious engineering obstacles (mainly the area along 30th Street Station, how to get that many lanes thru there without filling in part of the Surekill River) but a plan needs to be developed.

Basically, you would need to send one direction up and over the other direction, as well as over the surface streets.  But no one will like to triple deck this highway and block the views of the buildings in the area.

Triple decking could keep the expressway below the surface streets, but the lowest level would be at least partially below river level, meaning a tunneled segment or partially tunneled segment.

[jeffandnicole]

There are some obvious engineering obstacles (mainly the area along 30th Street Station, how to get that many lanes thru there without filling in part of the Surekill River) but a plan needs to be developed.

Basically, you would need to send one direction up and over the other direction, as well as over the surface streets.  But no one will like to triple deck this highway and block the views of the buildings in the area.

Triple decking could keep the expressway below the surface streets, but the lowest level would be at least partially below river level, meaning a tunneled segment or partially tunneled segment.

I was thinking a skyway top deck, rather than digging down!

[Chris19001]

There are some obvious engineering obstacles (mainly the area along 30th Street Station, how to get that many lanes thru there without filling in part of the Surekill River) but a plan needs to be developed.

Basically, you would need to send one direction up and over the other direction, as well as over the surface streets.  But no one will like to triple deck this highway and block the views of the buildings in the area.

Triple decking could keep the expressway below the surface streets, but the lowest level would be at least partially below river level, meaning a tunneled segment or partially tunneled segment.

Keep in mind around at Market Street you have an existing perpendicular tunnel down there that holds both the Market Frankford El and the subway surface trolleys.  I'm not going to pretend I know their level, but I would imagine they are relatively deep to get under both the river and the heavy tracks at 30th Street Station.  However, any above the ground expansion would be DOA to the stakeholders of the area.  (Its considered a transit district for a reason)

[Alps]

There are some obvious engineering obstacles (mainly the area along 30th Street Station, how to get that many lanes thru there without filling in part of the Surekill River) but a plan needs to be developed.

Basically, you would need to send one direction up and over the other direction, as well as over the surface streets.  But no one will like to triple deck this highway and block the views of the buildings in the area.

Triple decking could keep the expressway below the surface streets, but the lowest level would be at least partially below river level, meaning a tunneled segment or partially tunneled segment.

The engineer in me cringes at anything below river level that isn't enclosed for its entire stay there (i.e. a tunnel). Ain't no one paying to run pumps 24/7.

[Beltway]

Triple decking could keep the expressway below the surface streets, but the lowest level would be at least partially below river level, meaning a tunneled segment or partially tunneled segment.

The engineer in me cringes at anything below river level that isn't enclosed for its entire stay there (i.e. a tunnel). Ain't no one paying to run pumps 24/7.

I was thinking of something like a longer version of the open approaches to an underwater tunnel where the top of the retaining wall is higher than the river level (flood stage to be precise), if the bottom of the grade doesn't need to go deep enough to where an open top wouldn't work.