Walkable West Palm Beach


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Southern Boulevard bridge: Another bridge that needs an underpass

FDOT is holding a public meeting concerning the Southern Boulevard bridge replacement project.  On this blog, we’ve been calling for physically protected bike lanes on this bridge as well as an underpass in a series of blog posts written when the project was in design phase in 2015:

We can do better. One only needs to look north to the West Palm Beach side of the Royal Park Bridge for an example of a world class project executed by FDOT and the City of West Palm Beach.

We need to insist on a great Southern Boulevard Bridge. If you don’t insist on a great project then you are going to get the bare minimum in pedestrian and bicycle accommodations. Remember that the new bridge be will around for at least 75 years. Many of us will not be around to see the replacement of that bridge. Right now the current plans are just lines on paper that aren’t set in stone. FDOT has recently decided to spend an additional $12 million on the project to build a temporary bypass bridge. How about spending a little more to have proper bicycle facilities for the next 75 years?

How to make a great Southern Boulevard Bridge over the intracoastal

How to make a great Southern Boulevard Bridge – Part #2

The bridge design currently calls for unprotected “buffered” bike lanes and 6′ sidewalks. Adequate, but not ideal.

The good: 7′ buffered bike lanes over the bridge. This is an improvement over early renditions of the bridge which had unbuffered 5′ bike lanes sharing the shoulder.
The bad: Still no physically protected bike lanes on the bridge.
The ugly: Zero thought given to bicyclists at the intersection with Flagler Drive. Ideally, this could have been a place to put another underpass such as under the Royal Park Bridge that completely separates bikes and pedestrians from the vehicular traffic. Disappointing to see the city miss another opportunity to create more world class walking/biking facilities. Ultimately, this is an FDOT bridge, but if it was possible on the Royal Park bridge, why isn’t it possible here?

We need to demand more from FDOT, even if that involves some cost sharing from the city. Bridges have a long lifespan and we only get one shot to get it right. Adding an underpass later is sure to be more difficult and more costly, if it is possible at all.

southern intersection.PNG

Meeting details below

 

Southern Blvd Bridge  Invitation Flyer.PNG

 

Southern Blvd Bridge Invitation Flyer


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Bridges, bike lanes, and Tri-Rail bike cars: Recent media coverage

In case you missed it: Walkable West Palm Beach was interviewed for two stories this week that ran in local newspapers. Angel Streeter of The Sun Sentinel wrote a story on bike lanes and bridges, and Joe Capozzi of the Palm Beach Post did a story on the new bike cars on Tri-Rail trains.

bike-car-one

New Tri-Rail bike car has space for 14 bikes. Photo: The Palm Beach Post


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How to make a great Southern Boulevard Bridge – Part #2

Since our last post the WalkableWPB team has been busy researching the proposed design of the Southern Boulevard Bridge and we have crafted an alternate design that would provide proper bike and pedestrian facilities with a $1.15 million dollar cost savings from the current FDOT proposal, shown in the following rendering:

Southern Boulevard Bridge - FDOT

Southern Boulevard Bridge – FDOT

The current design is very aesthetically pleasing and even pedestrians have been taken into consideration by providing a pergola on the bridge as shown here:

Southern Boulevard Bridge - FDOT

Southern Boulevard Bridge – FDOT

Everything is so perfect that you would want to buy a post card of the future bridge. Unfortunately, if you dig a little deeper you will find that the beauty of the proposed bridge is only skin deep. As we pointed out in our prior post, the proposed Southern Boulevard Bridge fails at providing pedestrian and bicycle facilities worthy of its $90 million price tag. The bridge provides narrow 6′ wide sidewalks (compared to 8′ wide sidewalks on the Royal Park bridge to the north) and a painted white line provides protection to cyclists in the automobile shoulder. It gets even worse on the island, where 5′ wide sidewalks are provided. One a positive note, the latest drawings we received from FDOT now show a 7′ wide buffered bike lane for the island section. However, providing physically buffered bike lanes or widening the 5′ sidewalk to an 8′ wide multimodal path is a much better solution when you have a road pass through a linear park.

The proposed pergolas and overlooks on the bridge make one think that FDOT is really trying to provide first class pedestrian accommodations. However, the proposed narrow sidewalks aren’t in keeping with that vision. It appears that the design has become so focused on aesthetics that everyone forgot who the aesthetics were intended to benefit. All the landscaping, sophisticated bridge design, and Mediterranean Revival architecture doesn’t matter if you don’t create a space where people feel safe walking and biking.

So what could be done differently?

In order to create an environment where people feel safe walking and biking the sidewalks on each side of the bridge need to be widened to a 10′ width. This would allow for a bike lane and sidewalk to be placed behind the protection of a barrier. This configuration would be similar to this proposal:

Approved-for-the-cambridge-street-bridge-over-i-90 www.bostoncyclistsunion-org

Approved-for-the-cambridge-street-bridge-over-i-90 http://www.bostoncyclistsunion.org

Better bicycle and pedestrian facilities can be provided on this bridge for less money; in fact, approximately $1.15 million can be saved from the current design. An explanation follows.

In order to have 10′ wide sidewalks we must find four additional feet on each side of the bridge. Let us start with FDOT’s current bridge proposal. (Note the 6′ wide sidewalk on the right side with two people walking side by side. They must have shrunk the people!)

FDOT Proposal for Southern Boulevard Bridge over the Intercoastal

FDOT Proposal for Southern Boulevard Bridge over the Intercoastal

First, let us look at the automotive shoulder width in our quest to find 4′. At the December 11, 2008 public hearing an 8′ wide shoulder was proposed. Somehow since 2008 the shoulder grew 2′ to a 10′ width. An 8′ shoulder is perfectly adequate to park a broken down car or truck. In fact 8′ is the FDOT standard width for a parallel parking space. FDOT’s current version of its Plan Preparations Manual (PPM) figure 2.0.2 – Bridge Section allows for an 8′ shoulder for “low volume” undivided bridges. So we have found 2′ of the 4′ that we need for each side at no additional cost.

The next place to look is the 12′ wide travel lanes. When choosing lane widths it is helpful to consider context. The project is in an urban area with a traffic signal at the bottom of the bridge on the West Palm Beach side along with a 35 MPH speed limit. FDOT’s one size fits all policy requires a 12′ wide travel lane for an undivided roadway. A 12′ wide travel lane on an undivided highway makes a lot of sense if you have a 55 MPH rural two lane state highway such as SR-710 (Beeline Hwy.) in the northern part of Palm Beach County, but it makes absolutely no sense on an urban bridge with a 35 MPH speed limit. An identical City or County bridge in Florida is allowed to have 11′ wide travel lanes. Cities and Counties in Florida use a less stringent design manual based on national standards. If we go from 12′ to 11′ lanes we now have 3′ of the 4′ required feet.

Now that we have right sized the lane and shoulder widths we will look at the potential cost savings in the type of bridge proposed. The current FDOT renderings depict a post tensioned slab bridge for the main channel bridge. FDOT’s Draft Bridge Development Report (BDR) found that a conventional prestressed concrete I-beam girder was a feasible structure at a cost savings of approximately $2.16 million dollars over the post tensioned slab option. ($134 / sq.ft. prestressed I beam, $171 / sq.ft. post tensioned slab). (957′ long X 61′ wide X $37 sq. ft savings).

With the $2.15 million dollar cost savings we can add the missing one foot of width to each side of the bridge to provide our 10′ wide sidewalk. Using FDOT’s square foot bridge costs it is estimated that adding 2′ of bridge width for 1,080′ of conventional prestressed I-beam bridge ($134/sq.ft.) and 228′ of bascule bridge($1,494/sq.ft.) would cost $971,000. So a 2′ wider conventional prestressed concrete I-beam bridge would actually cost $1.15 million less than the current proposed post tensioned slab design.

In the interest of keeping the post short an analogy would be useful for these two types of bridges. The prestressed concrete I-beam is the Honda Accord of bridges – boring, reasonably priced, and reliable. The post tensioned bridge is the Ferrari of bridges. FDOT’s own bridge development report identified the post tensioned bridge as being higher risk than the prestressed concrete I-beam. The risk is due to the post tensioned slab bridge being a custom design and needing significantly more quality control in construction. Mistakes can happen. The 2007 collapse of the I-35W highway bridge over the Mississippi River in Minneapolis, Minnesota was due to a design flaw.

Perhaps the best question to ask as a taxpayer is what type of bridge would a private toll company, interested in maximizing profit, choose? The answer would be the lower cost, tried and true durable bridge. There is nothing wrong with a signature bridge if you can afford it, but there is something wrong with a signature bridge that provides substandard facilities for the user of the bridge. It is important to get this right. If you are reading this post then you will probably not be alive when the future Southern Boulevard bridge needs to replaced.

Action item: Ask FDOT, Town of Palm Beach, and the City of West Palm Beach to provide wider sidewalks on the both the bride and the island. Go to the Public Meeting this Wednesday, March 11th at the St. Catherine Greek Orthodox church and ask for wider sidewalks.


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How to make a great Southern Boulevard Bridge over the intracoastal

In recent weeks the Florida Department of Transportation (FDOT) has issued new policies that makes one think they are finally treating all modes of transportation as equal and understanding that our road rights of way have tremendous place making potential. These policies include buffered bike lanes and making highway beautification a design objective.

So we have a Department that is finally starting to get it, but the Southern Boulevard Bridge is a $90 million project that had its study completed on May 12, 2009 under the old paradigm that created a roadway network with the dubious distinction of having the most bicycle and pedestrian fatalities in the country.

Shown below is the current bridge proposal:

FDOT Proposal for Southern Boulevard Bridge over the Intercoastal

FDOT Proposal for Southern Boulevard Bridge over the Intercoastal

The design is an unimaginative slightly improved replacement of the current bridge. Bicycles get to use the car shoulder and minimum width sidewalks are provided for pedestrians.

The highway section on the causeway is even worse. Unbuffered bike lanes placed right next to the travel lanes and narrow sidewalks

SR-80 Intercoastal Bridge causeway section

SR-80 Intercoastal Bridge causeway section

There have been cyclists fatalities on other intracoastal bridges in Florida with a similar design. The way to build bike facilities to prevent these fatalities is to provide separation of the cyclists from the roadway. This is a relatively new concept in American highway design, but it makes so much sense once you see it. Below is a recent example of where the bike lanes were placed behind the barrier next to the sidewalk.

San Francisco-Oakland Bay Bridge Protected Bike Lanes

San Francisco-Oakland Bay Bridge Protected Bike Lanes

Would you rather ride your bike behind a barrier or next to a car with a white line providing protection?

In addition to being a safety feature these buffers can also be an aesthetic improvement. Below is a rendering of a citizen group’s plan to add buffered bike lanes to the Rickenbacker Causeway in Miami.

Plan Z Rickenback Causeway - http://planzmiami.com/

Plan Z Rickenbacker Causeway – http://planzmiami.com/

In the rendering above it is easy to imagine the causeway becoming a linear park.

We can do better. One only needs to look north to the West Palm Beach side of the Royal Park Bridge for an example of a world class project executed by FDOT and the City of West Palm Beach.

RoyalParkBridge

Royal Park Bridge multimodal path along intracoastal

We need to insist on a great Southern Boulevard Bridge. If you don’t insist on a great project then you are going to get the bare minimum in pedestrian and bicycle accommodations. Remember that the new bridge be will around for at least 75 years. Many of us will not be around to see the replacement of that bridge. Right now the current plans are just lines on paper that aren’t set in stone. FDOT has recently decided to spend an additional $12 million on the project to build a temporary bypass bridge. How about spending a little more to have proper bicycle facilities for the next 75 years?

How you can help: Email the FDOT project manager and tell them you want a safer bridge for bicyclists and pedestrians!

FDOT Project Manager:

Vanita Saini, P.E.

FDOT District IV

3400 West Commercial Blvd.

Fort Lauderdale, Florida 33309-3421

Phone:    (954) 777-4468

Toll Free: (866) 336-8435 x4468

E-mail: vanita.saini@dot.state.fl.us

Contact form: http://www.southernblvdbridge.com/contact.html