Q: Why does it take six months to replace a bridge on a two-lane, paved road?
A: Because there is no incentive for the winner of the bid to do it any faster.
It used to take US stamping plants the better part of a week to change over the dies on a major stamping line. Because of the slow change-over, the "economically viable run" measured in the tens-of-thousands of hoods or fenders or roofs.
Then the Harbour group started documenting how quickly the Japanese companies could change over a line.
It now takes all of a minute to change the presses. The ram (the part that comes down) lowers the punch onto their respective dies. Pins are pulled hydraulically. The die/punch sets are pushed out of position by the new sets that are sitting on roller tables and exactly the right height. The new set rolls in. The old sets roll onto another set of tables on the other side of the press-line. Hydraulics shoot pins to lock punches and dies and the press starts cycling.
Just throwing some numbers on the table. AAA estimates it costs about 82 cents a mile to drive 10k per year. The IRS allowance is 56 cents. Splitting the difference is 69 cents a mile.
Let's assume a typical detour is additional three miles. That is $2070 per thousand vehicles.
Now assume that the detour adds seven minutes of time. Further assume that every vehicle is single occupancy and the time is valued at the current Federal minimum wage of $7.25/hour. That is an additional 84 cents per driver or $840 per thousand.
This ignores secondary effects like incremental traffic congestion along detours and the impact it has on those drivers.
This math would be greatly enhanced with real data but a cost-to-society of $3000/thousand vehicles is defensible. If that cost savings were split between "society" and the contractors replacing/repairing the bridge, then the contractor would receive a bonus of $1500/per day on a bridge that saw 1000 vehicles per day.
I know I have readers with a wealth of experience. If it were a priority, is there any reason why it would take more than seven calendar-days to replace a bridge...assuming the steel and concrete and workers and equipment showed up when needed? Would they even break a sweat?
With proper incentives a bridge repair project can go VERY quickly. The contract to repair the bridges damaged during the Northridge earthquake. The contractor got a $14.5M bonus for finishing 74 days early.ReplyDelete
I've often wondered why construction projects along the interstates took so long. Think it has much to do with the way the bid packages are laid out.ReplyDelete
If a bridge repair or freeway repair was bid as a non-stop construction project, like the vidyo above, proper pre planning would allow companies with nimble crews to make kamikaze attacks (but Building bridges) with minimal *public* impact (downtime).
Leave it to you to present the data so eloquently, ERJ.
As above, 'very quickly' with right incentives.ReplyDelete
Atlanta I-85 destroyed by fire Mar. 30 2017
Re-opened road mid-May, approx *4* weeks construction.
Contractor made millions from completion incentives.
I've no doubt a lot of construction good ol' boys got new trucks from there next paycheck.
Why doesn't the party soliciting bids demand a faster completion time? Bonus for early, penalites for late.ReplyDelete
You would think the contractor would end up money ahead with a faster completion rate too. Pay the crew for 30 days and collect a check vs pay them 45 and get the same check... in 90 days that's 3 projects vs 2 completed, 50% gross pay raise for the contractor.
Unfortunately, as far as I know there are incentives for slow work - for example, the contractor usuygets paid for each day equipment is on site, cones block the road, etc.Delete
Combined with lobbying at the state level and rhreatsyof lawsuits, in many cases contractors write their own contracts and make them as favorable as possible to themselves. It is also why we constantly see lane closures far in excess of actual work - because the contractor is paid to post and maintain the closure, so they have a motive to make it as large and long as they can.
On concrete projects, it could have to do with the fact that the concrete has to cure for a certain amount of time.ReplyDelete
I know when we were pouring slabs with post tension cables, the minimum was 7 days before testing the cables.
The Northridge repairs ran that fast because CalTrans made every effort to make the project go as fast as possible, and it came at a cost to. The final accounting showed the construction costs doubled and the bonus was as big as the original contract, so the state paid 3x the original estimate to get the bridge done that fast. Even with the higher costs, the economic cost of 341,000 cars per day on alternate routes made the whole thing a net savings, I've never heard any complaints about price gouging on those repairs and I worked near Northridge at the time of the earthquake.ReplyDelete
In Pennsylvania, the PennDot contract graft is legendary, so the construction times are Looooooooooooooooooong.ReplyDelete
When you change that die are you also changing the steel/aluminum coil or sheets you're feeding into the press? How about the work instructions going along with the job? More importantly you left out the union contract, which played a big part in that timelag.ReplyDelete
Work instructions are called "Recipes" in the stamping plant and are sacred.
Union at GM Lansing Delta willing to be flexible in exchange for jobs. Not every local is like that.
There's a video somewhere from Europe where they made the bridge, a highway overpass, and changed it out overnight - it was ready for the morning rush hour. It's a time lapse video, I'll see if I can find it.ReplyDelete
Well, this ain't it, but here's an example of an overnight 'slide-in' that was done in Florida.Delete
My perception is that much of the delay is due to dead-time. That is, waiting for the cement truck to show up.ReplyDelete
I hate to write this, but the solution might be for the Department of Transportation to buy five loads of concrete a day per area so the various construction sites are not competing with each other, and then stagger the construction start-dates round those buys (and those of steel etc.)
The jobs could "zipper" for resources rather than be in competition. Leave the old bridge in-place until all of the necessary resources are aligned and then go like the dickens.
I know that with the North Carolina DOT, there has traditionally been no incentives offered to contractors for finishing early. This is due to our legislature being unwilling to appropriate such funds.ReplyDelete
My experience is oil and gas construction and most of the inefficiencies boiled down to two areas, the first is related to the sloppy engineering preparedness leading to incomplete contract specifications and deliverables, contracting companies see these during the bid preparation and know that change orders will be there for the taking. Change orders gum up the process, they require additional approvals, funding, reviews etc. (and time is money)ReplyDelete
The next barrier involves the sunk costs of the contractors, they have equipment, scaffolding and process and their motivated to put what the currently have to work. They view new and more efficient technologies as a threat because they can’t justify the same costs for faster completion using fewer people and less equipment.
Most organizations aren’t sophisticated enough to develop a win-win approach to project management and most contractors don’t trust the Companies enough, being opportunistic is their comfort zone.
Back in the mid-80s the rule-of-thumb I was told was to figure +25% costs for change-orders as a starting point.Delete
It is a matter of what waits for what . . . in the doctor's office, his view is very efficient - he goes from waiting patient to waiting patient. You wait for him.ReplyDelete
Building a house waits for trades, materials, etc. If it's the other way, costs go up exponentially with every delay.
The doctor's scheduler is probably working on the basis of 20% no-shows. The cost drivers are not just the ratio of the doctor's costs but the lack of smoothness in incoming patients.
An oil refinery is incredibly expensive and oil is relatively cheap but they run it with very little excess inventory because pipelines are very, very reliable at delivering oil/gas and because inventory is a pain in the butt.
There is a limit to how fast you can accelerate some things. Concrete is a big one. Fast curing mixes exist but do not have the long term durability of slower mixes. Building a bridge with 'slower' and more durable materials on the side of the road and walking it into place is a good trade off but requires a funding agency that places a value on the time of the road user. My agency has done a lot of these but it wouldn't happen without a legislature that sees the 'value' in minimizing travel time delays.ReplyDelete
I know that the legendary, decades-long delays in repairing/expanding the Hutchinson River Parkway and I-95 around New York City (1960s-1990s) were due to graft, involving both .gov officials and organized crime.ReplyDelete
Having lots of construction zones with double fines for speeding means more municipal income.ReplyDelete