I am sure pedestrians and bicyclists will appreciate being able to cross an ugly bridge a few feet from the roar of freeway traffic versus having an entire historic cantilever bridge to themselves.
I appears the new bridge is not a through truss, based on data on the MODOT page.
And the new bridge will have a pedestrian/bicycle lane, so there is no use for the historic span.
In the list of excuses for replacing the 1935 span, the page says "... has reached a point where it needs regular preventative maintenance." I guess MODOT figures that any bridge needing maintenance needs to be replaced. Stupid. Maintenance is more cost effective than repair, which is more cost effective than replecement. Maybe it's that politicians like to put in new bridges so they can earn brownie points by naming the bridge for big-named people.
The attached image is an artist rendition extraced from a PDF I found on the MODOT site
And another thing I forgot to mention, is that cost of propert acquisition would be non existant if the current rights of way are used for the new bridge, instead of moving it farther upstream.
Tony, MODOT people always cite safety and liability concerns when it comes to leaving an old bridge there for pedestrain use, IMO... keeping bicycles and such off of a busy bridge is good for safety, I just don't see how it can be more expensive to turn an old bridge into a pedestrain bridge, than it would cost to demolish it. I understand that tweaks would have to be made to make a twin... but I was going on the assumption that the twin would be RIGHT next to the other, so the topgraphy should not be THAT much different, not 100 feet away. Also, the fact that bridges are routinely moved and reused at completely different crossing made me think that this should work. the twin bridges on I-270 at Chesterfield certainly serve their purpose well, I don't see why the Daniel Boone bridge couldn't be the same.
Having worked for an engineering firm, I do agree that some "tweaking" to the design would need to be done. The difference in topography would require some adjustments to the substructure and approach modifications at the least. But I do believe the same basic design could be used that would save the taxpayers a great deal of money in the long run.
Two through truss Camelback spans in Delaware County, Indiana came from the same design back at the turn of the century. The Priest Ford Bridge was built by the Indiana Bridge Company in 1897. Then in 1902, IBCo. used the same plans to build another bridge downstream at High Banks. The bridges were on totally different types of substructures with uniquely different approaches, but the trusses were (are) identical.
As far as the historic structure goes...I'm all for leaving it in place if for nothing more than pedestrian usage. But we're talking Missouri here...so I don't expect it will occur.
If MoDOT actually cared about saving taxpayer dollars, they wouldn't waste money demolishing the historic bridge after they build the replacement bridge.
While I'm sorry to see the replacement of this bridge, I should comment on the question of simply reusing the newer design.
Any engineering project requires the final seal of a licensed professional engineer. They are paid for the design and are professionally liable for the proper performance of the design--if the bridge design is defective, the engineer is liable. Clearly a recycled design would not have have been created for the exact location or under the same design code and other legal requirements. The engineer responsible for the original design clearly can't be held responsible for a design used in a way in which it was not intended, that is, for a bridge in another time and location.
Even building a seemingly identical bridge requires a study of the ground conditions at the exact location of the new piers. Regulations and codes may have changed and the engineer needs to certify that the design meets current requirements. Tie-in to existing roadways will be different, traffic flow during construction will have to be arranged, new construction materials and equipment need to be taken into account, etc. Materials may be sourced from different vendors (can you still buy steel from the same mills as they did 20 years ago?) and have different specifications. Even the wind loads may be different--the effect of the parallel span on the wind will be different from that of the older bridge.
Although it shouldn't cost as much as requesting a totally new design, there will be a lot of original engineering work required before a set of plans for an "identical" span will be ready for approval.
I'm grateful at least it's a through truss.
Because it is too fiscally responsible and makes WAAAAY too much sense!
Sorry...couldn't avoid a response that wasn't dripping with sarcasm.
Here's something I've always wondered. The articles state that money allocated includes design, and property acquisition for the new bridge. WHY does the state pay money for a new bridge to be designed? Does anyone know why they don't save taxpayer dollars and simply use the design from the 1991 span, and build an exact twin? What is their reasoning for not doing this?
Design-build. That is how the new bridge would be built. Once it is complete, it would carry traffic into St. Louis County that the existing 1991 span now does. The 1991 span would be reconfigured to handle the traffic going into St. Charles County, that the old bridge is now doing. The 1935 bridge will be torn down later. Link: http://www.modot.mo.gov/stlouis/major_projects/NewDanielBooneBridge.htm
And MODOT is scraping the plan of keeping the older span for pedestrian use, citing continual repairs and maintaining the span for such use.
The work is now projected to begin by late 2012 and take about three years to complete.
The following is a link to the bridges and approaches during the Great Flood of 1993.
MoDOT has decided against keeping the original Boone span for a frontage road after a replacement span for I-64/US-40 is built. Of course MoDOT doesn't know when the new span is going to be constructed since there's no funding for it.
ST. LOUIS POST-DISPATCH
Recent inspections of the 73-year-old westbound segment of the Daniel Boone Bridge have spurred an end to plans to keep it open for outer-road traffic after a replacement is built.
The Missouri Department of Transportation decided it would cost too much to keep maintaining the old span indefinitely, spokesman Andrew Gates said Tuesday.
He added, however, that MoDOT will continue to keep it safe for travel as long as it's used to take Highway 40 across the Missouri River between Chesterfield and St. Charles County.
"We will do what it takes to keep it open and safe," Gates said. "It may require more and more preventive maintenance."
Pictures of Daniel Boone Bridge on trip of 12.14.09 to St.Charles. One is water from van. All pictures are from traveling towards St.Charles.
Sharon, the current plan is to keep the existing bridges but add a third span. The 1937 span would then be used to carry a frontage road and possibly a bike lane. See:
The westbound span of the bridge is not up to interstate standards. MODOT says the bridge is currently safe. They are planning on sending a formal request to the FHA to continue the I-64 designation on the western section of the interstate. But there are plans to replace the bridge once funding becomes available.
The full article can be read here: