Main St. Bridge: Repurpose? Replace?

[fieldafm]

I'm surprised no one mentioned the need/desire to close off a lane for a hot dog cart.  Obviously said cart should be placed at the apex of the bridge. 

Let's see if Tampa/Miami can top that!

The irony is not lost that the current administration is moving forward with many of the concepts from former Mayor Peyton's Big Idea- tearing down the Landing for a park, tearing down the Main St bridge ramps (which is actually a good thing), taking out River City Brewing and pushing development ang big capital spends to the Sports District.

https://www.metrojacksonville.com/article/2008-dec-peytons-struggles-the-big-idea

https://www.metrojacksonville.com/article/2007-apr-salvaging-the-big-idea-ii-preserving-friendship-fountain

https://www.metrojacksonville.com/article/2007-mar-salvaging-the-big-idea-i-kids-kampus-flex-space

[acme54321]

What ever happened to the bacon barge?

[fieldafm]

What ever happened to the bacon barge?

That person moved to Oregon.

[Steve]

What ever happened to the bacon barge?

That person moved to Oregon.

Holy cow. That was amazing.

We should keep this thread on track though.


BAD EXPERIENCE AT MOON RIVER PIZZA


OK....Starting NOW!

[acme54321]

SCREW THOSE PIZZA CHUCKING HIPSTERS!!! 

[bl8jaxnative]

The lanes are fine if people drive slow. I'm not sure of the speed limit there but people tend to gun it on the bridge. On the other hand, the AADT is only 13,700. Other than the off chance of capacity being preserved for in case of hurricane evacuation or I-95 being shut down, going down to two lanes with a cycle track could work too.

Speed limit is 30mph.  Cars regularly go 60mph.

My money is that the northbound vehicle's, the Geico vehicle, driver was distracted ( using phone, reaching for something in backseat, et al ).

2 lanes each way would be nice.  Curious how they'd do cycletrack with the open grate portion.  Not saying it can't be done, just curious what it would take.

[acme54321]

2 lanes each way would be nice.  Curious how they'd do cycletrack with the open grate portion.  Not saying it can't be done, just curious what it would take.

You can ride over it, its a little bumpy on a road bike but it's ok.

Personally, I think two lanes would probably be an issue during rush hour, periods of heavy traffic and events downtown.  Start with enforcing the speed limit and minimally invasive traffic calming installs like lane dividers and rumble strips.

Removal of the elevated bridge and dropping Main down to grade on the Southbank would really slow it down.

[tufsu1]

2 lanes each way would be nice.  Curious how they'd do cycletrack with the open grate portion.  Not saying it can't be done, just curious what it would take.

Chicago has figured out how to retrofit some of the bridges crossing the river - check out Kinzie Street

[fieldafm]

2 lanes each way would be nice.  Curious how they'd do cycletrack with the open grate portion.  Not saying it can't be done, just curious what it would take.

Chicago has figured out how to retrofit some of the bridges crossing the river - check out Kinzie Street

Yes, you essentially bolt/weld metal plates over the existing metal grating to provide a smooth and safe surface for cyclists to ride on. Its a very cost-effective solution. 

[Charles Hunter]

The potential issue with adding steel plates, or any solid surface, over, or in place of the open grating, is the weight.  The engineers will have to sharpen their pencils* to make sure [a] the bridge structure can carry the additional weight (like the Mathews could), and the lift mechanism will still work. 

* or run a few more model simulations

[Adam White]

The potential issue with adding steel plates, or any solid surface, over, or in place of the open grating, is the weight.  The engineers will have to sharpen their pencils* to make sure [a] the bridge structure can carry the additional weight (like the Mathews could), and the lift mechanism will still work. 

* or run a few more model simulations

I'm not an engineer - and I did not stay at a Holiday Inn Express last night - so I could be totally wrong. But given the relatively short section that would be covered (or partially covered) with plates, I wouldn't be surprised if the weight added is less than the weight the section would bear if it had to lanes of automobile traffic running over it. If I understand this correctly, you'd lose one traffic lane on each side and replace those with bike lanes (which would have steel plates over the grated section).

[Charles Hunter]

The potential issue with adding steel plates, or any solid surface, over, or in place of the open grating, is the weight.  The engineers will have to sharpen their pencils* to make sure [a] the bridge structure can carry the additional weight (like the Mathews could), and the lift mechanism will still work. 

* or run a few more model simulations

I'm not an engineer - and I did not stay at a Holiday Inn Express last night - so I could be totally wrong. But given the relatively short section that would be covered (or partially covered) with plates, I wouldn't be surprised if the weight added is less than the weight the section would bear if it had to lanes of automobile traffic running over it. If I understand this correctly, you'd lose one traffic lane on each side and replace those with bike lanes (which would have steel plates over the grated section).

I am not an engineer either, but I used to work where there were lots of them (which makes my "knowledge" perhaps more dangerous  ) - but I recall there being a difference between "static load" (the steel plates) and "dynamic load" (the traffic moving over the bridge). That's why those engineer folk will have to sharpen their pencils and get out their slide rules* to figure whether the bridge can handle the changes.  My guess - probably "yes" as we are told that "in the old days" (bridge was opened in 1941) things were overbuilt and built to last.

* slide rule, an ancient artifact - for you young whippersnappers (and get offa my lawn)  https://www.math.utah.edu/~alfeld/sliderules/

[Adam White]

The potential issue with adding steel plates, or any solid surface, over, or in place of the open grating, is the weight.  The engineers will have to sharpen their pencils* to make sure [a] the bridge structure can carry the additional weight (like the Mathews could), and the lift mechanism will still work. 

* or run a few more model simulations

I'm not an engineer - and I did not stay at a Holiday Inn Express last night - so I could be totally wrong. But given the relatively short section that would be covered (or partially covered) with plates, I wouldn't be surprised if the weight added is less than the weight the section would bear if it had to lanes of automobile traffic running over it. If I understand this correctly, you'd lose one traffic lane on each side and replace those with bike lanes (which would have steel plates over the grated section).

I am not an engineer either, but I used to work where there were lots of them (which makes my "knowledge" perhaps more dangerous  ) - but I recall there being a difference between "static load" (the steel plates) and "dynamic load" (the traffic moving over the bridge). That's why those engineer folk will have to sharpen their pencils and get out their slide rules* to figure whether the bridge can handle the changes.  My guess - probably "yes" as we are told that "in the old days" (bridge was opened in 1941) things were overbuilt and built to last.

* slide rule, an ancient artifact - for you young whippersnappers (and get offa my lawn)  https://www.math.utah.edu/~alfeld/sliderules/

Yeah, that makes sense. And, it occurred to me later that the bridge doesn't lift with cars on it - so your comment re the weight and the bridge being able to be raised make sense.

I do remember slide rules - I am "only" middle-aged, but they were still a thing when I was a young whippersnapper. I mean, nobody was probably using them anymore, but you'd come across them from time to time. I think maybe my dad had one.

[Steve]

Just put the metal plates on and see what happens. There's precedent - remember the giant, heavy, concrete planters that were once on the Riverwalk in front of the Hyatt (then Adam's Mark)?

[JaxJersey-licious]

Mind you these types of accidents are pretty rare but there may be a regional logistical issue making that stretch of road more dangerous.

Forget all those constant tropes about the driving abilities in other regions, many drivers in the South have the benefit in recent years of many of their heavily travelled roads expanded with additional wider lanes featuring bike lanes rarely utilized with ample median separation from oncoming traffic; and the areas where those roads aren't are in parts of town many suburbanites don't spend a lot of time in. Here in New Jersey, more of our major roads have a similar configuration to that stretch of the Main St. bridge unable to be improved  in any significant way or subjected to a 'road diet' which is why drivers in North Florida not only drive faster on their typical 4 lane roadways then their Garden State counterparts when congestion is not an issue, they are also less susceptible for any consequences in situations they suddenly become "distracted". And head on collision incidents are just as rare in Jersey even when thing like sudden snow squalls hit the roads probably because of the limitations to driving full tilt Florida-style.

Plus I wouldn't doubt there is a temptation for drivers not fond of dealing with the typical downtown street grid and congestion issues to treat Main St. like it was the Gatornationals. What was the average speed of cars traveling down the old Hart Bridge ramps again?

Alas, I see more of these types of accidents even here in New Jersey due to less road congestion stemming from the rise of telecommuting and distanced-everything brought about by the Covid-19 outbreak: People driving at higher speeds, distracted driving habits rising, and ultimately letting their guard down on practicing safer driving in general.

The lanes are fine if people drive slow. I'm not sure of the speed limit there but people tend to gun it on the bridge. On the other hand, the AADT is only 13,700. Other than the off chance of capacity being preserved for in case of hurricane evacuation or I-95 being shut down, going down to two lanes with a cycle track could work too.

2 lanes each way would be nice.  Curious how they'd do cycletrack with the open grate portion.  Not saying it can't be done, just curious what it would take.

The only time grates are an issue with bicyclists is when they are wet. Any sudden shift of weight on a hollow wet grate can have you suddenly on the floor in less than a second. A metal cover would help but ideally you would want to pave the grate opening over.  And that's why it's just safer to take the few extra minutes and just used the Acosta or better yet the new Fuller Warren path once completed.