It is commented on that many modern large US engineering projects take longer than those that that proceeded them, even though they are smaller in scope and have the advantage of modern technology (e.g. 2nd Ave Subway or Eastern Span of the SF Bay Bridge). Extra red tape (including modern US not being OK with tons of workers being killed or injured in the process of building a large engineering project) are often cited for this.
So my question is at what point was US civil engineering most efficient? Presumably technology increased efficiency up to some point in the 20th century then other factors came into play that counteracted advances in engineering tech up to the point that now civil engineering projects are less efficient (in terms of cost and time taken to complete) than they were in the past. At what point did we reach “peak efficiency”, and you can say that US civil engineering has never been more efficient than it was in year XXXX, either before or since.
A major change is that there are very few Greenfield projects anymore [The Greenfield project means that a work which is not following a prior work. In infrastructure the projects on the unused lands where there is no need to remodel or demolish an existing structure are called Green Field Projects.] So nowadays when a new bridge is being built it is almost always a replacement for an existing bridge which needs to connect with an existing highway system on which it is imperative to keep the existing traffic moving on the old bridge until the new bridge is ready. This adds enormously to costs and time delays in construction.
this. it’s a lot easier and faster to build a bunch of stuff when you don’t have to care about what’s already there. when you have to replace something with minimal disruption, then that’s a far harder problem.
In addition to discounting the cost of worker’s lives, the OP also discounts the cost of environmental degradation and similar factors. That said, there is also the costs of things like nimbyism and the like. The 2nd ave. subway would be a lot cheaper if they built it by cut-and-cover.
I don’t think it’s correct to assume that just because the eastern span of the San Francisco–Oakland Bay Bridge was replaced (rather than the whole thing as was built in 1936), the scope of the work was smaller. Wikipedia says that “the replacement span is engineered to withstand the largest earthquake expected over a 1500-year period, and it is expected to last at least 150 years with proper maintenance.” That level of engineering almost certainly exceeds that of the original bridge.
I agree that the opening post question as phrased is fundamentally flawed.
“Efficiency” is defined there, as “cost, and time taken to complete.” That’s a common, but defective way to measure efficiency. It ignores, or at least obscures, the question of whether the completed task, actually fulfills the full list of goals it was intended to take care of. And usually, it ignores how truly tricky the subject of “costs” has always been.
I personally would say that American civil engineering at least has NEVER been more truly efficient than it is now. ESPECIALLY because of the POSITIVE contribution of MOST of the modern regulations. Those regulations are designed, in addition to making the workplace itself more safe, to see too it that whatever IS built, actually performs as needed, does so for a much longer time than previous “efficient” constructions, and more important, sees to it that the particular effort in progress, isn’t going to cause an additional set of new problems going forward.
As some have hinted above, if you play a coy game with your definition of “costs,” shutting down an entire city while a bridge is being built, so that the bridge can be constructed in record time, only looks great on the cost ledger, if you ignore the huge disruption of all commerce, and the tremendous rise in cost of living that everyone in the city suffers as a result.
This kind of manipulation of costs and misunderstanding of real efficiency, is at the core of a very VERY bad fad political trick being played on the United States for the last half century. Pretending that all regulations are the result of petty emotional wimpiness, or even actual intentional sabotage of American Productivity, has become so common, that many who delude themselves that it’s true, now simply roll their eyes at each other when anything related to thinking more carefully about ALL factors in a situation, and then cheerfully bash their way forward with whatever they want to get for themselves.
Expected by whom? The new span is already requiring repairs due to poor construction.
Without getting into GD territory (possibly optimistic to expect) it seems a pretty a obvious non-political point that civil engineering works are less efficient than they were in the past (the reasons for that are up to debate).
It has been controverted in this thread, by people raising what seem to be to be reasonable objections or queries, and you haven’t dealt with the points raised.
Rereading the OP, you seem to be using “efficiency” as a synonym for “speed” (modern civil engineering projects are inefficient because “they take longer than those that preceded them”). That’s a fairly non-standard understanding of “efficiency”, and not remotely like one that engineers themselves are likely to employ.
Maybe what seems obvious to you is not obvious to us because we haven’t understood what you mean by “efficient”? Try rephrasing your question without using the word “efficient”, and see if we can make better progress.
The scope and funding of modern “large” projects is often less than previous ones, so it’s not a fair comparison.
E.g, the US interstate highway system went from zero to 50% complete (20,000 miles) in only nine years – 1956 to 1965. But the project cost $511 billion in 2015 dollars. It was built in a less populated era and largely in rural settings. It was 90% funded by the federal government.
Today it could take nine years to build a little bypass around a city. That doesn’t mean it’s less efficient. Rather it was given to the lowest bidder who could do it cheapest with less priority on time. It’s the difference between mass production vs “piece work”. If you funded a $511 billion rural superhighway project today with priority on rapid completion it could be done pretty fast.
Not necessarily. Current analysis techniques are more sophisticated, which allows for designs that are less conservative/more efficient. In the past, to make up for uncertainty, the safety margins were often higher.
In that case the process is less efficient.
[ No political meaning; just that choosing clothes by cheapness and spending a lot of time establishing the cheapest might not result in the optimal result. ]