Commentary: GIBA says bridge bumps are popular

GIBA’s maintenance staff has finished the installation of the third new 20 mph speed bump cushion. These traffic calming devices are being installed on the Boca Grande Causeway lanes on both sides of the GIBA’s historic swing bridge to help slow down traffic to the posted speed limit of 20 mph on the swing bridge.

Slowing traffic down to 20 mph is required as a safety issue, yet it also provides another hidden benefit. It allows customers to enjoy the very scenic views of the Intracoastal Waterway, a variety of boat traffic and aquatic wildlife, and very unique panoramic views of Lemon Bay to the north and Gasparilla Sound to the east as they travel 20 mph while crossing the historic swing bridge.

Last Friday’s installation was in the “to island” lane about 600 feet past the toll plaza and just prior to the large “bridge opening” traffic safety gate and signals, which flash to warn drivers to stop prior to the bridge gate being lowered and the swing bridge opening for boat traffic.

This is the third in a series of four speed bumps being installed. When completed there will be a speed bump in each swing bridge lane just prior to and after the two traffic gates at both ends of the swing bridge.

Just five seconds more

The difference in driving time to drive 20 mph for the 300-foot distance across the swing bridge deck in between the two speed bumps is only five more seconds, if you simply decrease your speed from the 35 mph speed limit prior to the bridge, to the posted bridge safety zone speed limit of 20 mph.

Last Wednesday, GIBA installed the first speed cushion for the lane departing the Swing Bridge heading to the island.

On Thursday, GIBA finished installing the second speed cushion on the lane departing the island and approaching the Swing Bridge.

Friday morning, GIBA’s maintenance team installed the third speed bump in the lane exiting the toll plaza and approaching the swing bridge.

The final speed bump (toll plaza side on “off island” lane exiting Boca Grande) will be installed later, next week.

Signs

Standard FDOT traffic warning signs have been posted by GIBA staff according to state highway rules to alert all drivers by noting:

(1) REDUCED SPEED AHEAD (Posted Speed Limit is slowed from 35 mph to 20 mph)

(2) SPEED LIMIT 20 (For 10 years, the bridge and toll plaza area have been posted as a 20 mph safety zone, due to GIBA staff working in the area, crossing the roadway and working on the bridge)

(3) SPEED BUMP AHEAD (Advance Notice)

(4) SPEED BUMP (with an arrow) at the exact speed bump road location.

Just slow down

Essentially, if drivers simply slow down, when they approach the “Speed Reduced Ahead” warning signs and then drive the normal bridge safety zone posted speed limit of 20 mph (or less), they will have no problem safely transiting and clearing the black and yellow striped rubber speed cushions. Even low clearance sports cars like Corvettes, Jaguars and Mini-Coopers are having no problem with the 3 inch height, when they slow down to 20 mph.

Five-to-one for the bumps

There have been a few customers who don’t like slowing down for the “bumps” or are worried about someone behind them not slowing down. Yet, more than five-to-one we have received favorable comments. People understand the need to slow down to protect the bridge.

GIBA’s new speed cushions are the latest high tech product by Traffic Logix, a Canadian firm. They are made from recycled tires (rubber). They are easy to identify as they are black with yellow reflective safety stripes. The new speed bumps were recommended to GIBA by two Florida engineering firms: KCA (Tampa) and Hardesty and Hanover (Fort Lauderdale), and the Charlotte County sheriff. The installation of the new speed bumps for all four GIBA swing bridge traffic lanes was unanimously approved by GIBA at its February board meeting.

Just 3 inches high

The speed bumps are only 3 inches high at the highest point: The “approach ramp” is 3.5 feet long, followed by a flat “speed table” 3 inches high and 3.5 feet long, followed by a rear “roll down” ramp 3.5 feet long. So the total linear length of the entire “speed table” area is 10.5 feet long. The sections on the toll plaza side of the bridge are each 10 feet wide, the entire width of a lane. The section on the Boca Grande side of the swing bridge is 21 feet wide installed as one solid strip covering both lanes. This product has been successfully field tested and approved for traffic speeds up to 25 mph.

State of the art

The new GIBA speed bump cushions are a state of the art traffic calming solution, built from recycled tires, of durable rubber, with reflective yellow stripes which are easy to see. They should help solve several ongoing GIBA bridge structural safety issues, which have resulted from traffic speeding on the bridge. They will also help prevent costly swing bridge repair problems over time, such as:

• Additional breaking of welds on the steel swing Bridge deck.

• Further cracking in the aging (50-year-old) bridge deck support concrete beams.

• The dangerous practice, which occurs several times each week, of speeding drivers (usually coming “off island”) illegally and unsafely “running” the swing bridge traffic gates, as the flashing warning lights are on and the gates which block two lanes are in the process of coming down.

• The daily need for increased safety from speeding vehicles crossing the swing bridge for the GIBA bridge tender staff and maintenance staff, while they are working on the bridge or walking along the bridge performing routine safety and maintenance checks.

Bridge cracks

During the January 21 swing bridge inspection, the KCA bridge inspectors noted accelerated cracking in a main concrete swing bridge deck support beam, resulting from high traffic speeds and unwarranted vibrations. Just last week GIBA spent more than $100,000 to fully repair and restore a badly cracked swing bridge deck support beam. The emergency repair process inconvenienced thousands of Boca Grande toll customers, as GIBA was required to shut down one lane on the two-lane bridge, and go to flagmen controlled single lane traffic operations for an entire week, in order to fix the dangerous beam cracks. The KCA inspectors also noted in 2008 that many new steel bridge deck welds had been broken, due to high speed traffic, since last year’s annual inspection.

Enjoy the view

Slowing traffic down to 20 mph is required as a safety issue, yet it also provides another hidden benefit. It allows customers to enjoy the very scenic views of the Intracoastal Waterway, a variety of boat traffic and aquatic wildlife, and very unique panoramic views of Lemon Bay to the north and Gasparilla Sound to the east as they travel 20 mph while crossing the historic swing bridge.

GIBA believes these new traffic calming devices are a very simple, yet cost effective measure to assist in improving public safety on the bridge and to help protect and preserve the historic Swing Bridge, until a new replacement bridge can be designed and built.

Meeting slated

GIBA is hosting a informative, special “Future Bridge Designs” public meeting in two weeks on Wednesday, March 26 from 2 to 4 p.m. in the Auditorium at the Boca Gande Community Center. The meeting will provide a look at the future on what the new replacement bridge options for the 50-year-old swing bridge could look like.

GIBA is looking forward to receiving public input and ideas from commercial users, business owners, and island residents on the basic design options and on traffic lane, bike lane and pedestrian options.

Jim Cooper is executive director of the Gasparilla Island Bridge Authority.