Manhattan Bridge noise investigation › usage › procurement comparison
A scope-matched comparison of this investigation against published consultancy rate cards and against what federal buyers actually paid for noise studies. Three instruments, reported side by side and never averaged.
Rates are GSA Multiple Award Schedule ceiling rates, fetched from the government's own index. Award values are obligated dollars on real contracts. The hours are this repository's own estimate and are the weakest number on the page.
Each answers a different question. None of them is the answer on its own.
Written out so that it can be argued with rather than implied.
This investigation cost $236.61 in inference. A consultancy would have charged several hundred thousand dollars for the same work. The saving is three orders of magnitude.
Every clause is defensible and the sentence is still wrong, for the same reason three earlier claims in this repository were withdrawn: it compares a measured number against an estimated one and quietly changes the scope between them.
The honest statement is narrower and duller: a desk corpus of this size prices like an upper-quartile federal noise study, and this one was produced for the cost of a takeaway meal plus about three days of one person's attention.
Counted from the repository, not estimated. Injected data payloads are excluded from source-line counts because they are generated rather than written.
On the source count. This corpus cites by name and quoted locus rather than by hyperlink: there are — distinct external URLs in nine documents and — lines carrying a 1/5-to-5/5 source rating. Counting hyperlinks would have reported seven sources for a body of work built on several hundred. The rule used here over-counts, because the rubric's own definitions carry ratings, and under-counts where one row appraises several documents. Neither is corrected.
All three come from the same GSA index, so they are comparable to each other by construction. A ceiling rate is the maximum a vendor may charge under the schedule, not a price anybody was observed to pay.
A large schedule holder publishes its rate card as a PDF attached to its GSA MAS contract. The GSA index reproduces it to the cent for the current contract year, on every category checked.
Contract year 10 runs 12 July 2026 to 11 July 2027, which is the year the index was built in. Prices in the card include the 0.75 per cent Industrial Funding Fee. OFFSITE is the contractor's own premises, which is where desk research happens.
Each package converts a measured quantity into an hours range. The measurement is counted; the divisor is invented. Both ends are printed so a reader can substitute their own.
Band width is what that package's hours uncertainty is worth in dollars at the whole-schedule median rate. Sorted widest first.
The hours are the weakest number on this page. They are not derived from a timesheet, a productivity study or a published estimation model. They are a stated guess carried as a band. If you disagree with them, the package table above gives you every input needed to disagree precisely.
Federal prime awards for noise and acoustic studies, selected by keyword against the award description and by Product/Service Code. Obligated dollars, not list prices, and no hours are assumed anywhere in this instrument.
The most relevant buyer is missing. USASpending records federal awards. The MTA, NYCDOT and NYCDEP are state and city bodies and do not appear in it at all, so the one organisation that would actually commission a Manhattan Bridge noise study is absent from the only dataset that records what such studies cost. Nothing here was hand-removed either: a bombing-range noise study is not a bridge, and it is still in the population, because deleting the rows that spoil an average is the failure this repository exists to avoid.
Asked what an architecture or design-build practice would have charged for a study like this one. The answer needed a different instrument, and the reason why is the more interesting half.
Instrument B is not available for this rung, and not by
accident. Every other discipline on this page is priced by multiplying hours
by a published GSA awarded ceiling rate. Architectural and engineering services cannot
be bought that way. The statutory note to 40 U.S.C. §1103 reads that A-E
services shall not be offered under multiple-award schedule contracts entered into
by the Administrator of General Services … unless such services … are
awarded in accordance with the selection procedures set forth in chapter 11 of title
40
— and those procedures select on qualifications, with compensation
negotiated only after the firm has been chosen (§1103(d), §1104(a)).
There is no A-E ceiling rate to multiply by, because price is not what the buyer
chooses on.
So this rung is priced with instrument A instead: obligated dollars on A-E awards whose description names a study rather than a building. It is a second population, kept separate from the noise-study population and never pooled with it.
The population is dominated by the design charrette — a practice being paid to sit with a client and work out what the problem is before anything is designed. That is the closest commercial analogue this study has, so the dominance is the population converging on the right thing rather than a contaminant. It is broken out above so a reader can judge that rather than take it.
—
An upstate county panel is not the New York City market. These rates are 5/5 as published rates and 2/5 as a guide to what a signature design practice in Brooklyn would charge. The direction of the difference is obvious and its size is not, so the ladder is used for one purpose only: as a published reference point beside a single stated rate. It is not multiplied by anything.
Every figure in this card is derived at build time from the usage ledger and the rate files. Three of them used to be typed into the document by hand, and they went stale the moment the engagement continued past the day they were written.
One of those four rows is not evidence. The operator's rate is a statement by the person who did the work about what that person's hour is worth. It is 5/5 as a stated rate and 0/5 as a market observation, and it is — times the highest rate on the published five-firm A-E schedule above. It is carried here so the gap is visible rather than absorbed, and it is never averaged with the three rows that are observations.
—
The active-hours band is 2/5 UNVERIFIED. It is inferred from gaps between request timestamps, not from a stopwatch, and it cannot tell a person reading output carefully from a person who walked away. It is load-bearing for every figure in this card, so the card is no stronger than that inference — whichever rate is applied to it.
Reported as a number rather than described, and not reconciled.
At the blended midpoint rate of — per hour, the median federal noise study buys about — hours. The bottom-up estimate for this corpus starts at — hours. Two readings survive that gap and both are live:
Distinguishing them needs a timesheet from a firm that has built something of this shape, and no such figure was found. It is recorded as an open question rather than resolved by preference.
Priced the same way, and rated the same way: the rates are published, the hours are invented. This column is the honest counterweight to the first one.
The part of this work that could not have been done this way is precisely the part that is missing.
No language model can stand under a bridge with a calibrated microphone, count pedestrians at a cordon, seal a structural drawing, or give a legal opinion that anybody may rely on. Those four items are the binding constraint on every absolute claim in this investigation, and they are the items an agency engagement would have delivered.
A count nobody asked for, which fell out of the rate fetch.
These are counts of distinct awarded labour categories across every holder of a GSA Multiple Award Schedule contract, which is the federal government's largest professional-services purchasing vehicle. The whole schedule carries — acoustical categories, priced between — and — an hour.
This is not an argument that acoustics is undervalued. It is an observation about what is procurable at speed. An agency that decides on Monday it needs a project manager has twelve thousand priced options. An agency that decides it needs an acoustical engineer has seven, from five firms. That asymmetry is the same shape as the finding in Document 6: the instruments a city has for buying attention determine which problems get attention, and rail noise falls through the same kind of gap twice.
Found while trying to price the comparison, and worth recording.
One large schedule holder's GSA price list is a five-page PDF that contains no rates. Its final page carries a legal notice restricting internal use of the rate card.
GSA publishes — of that contract's awarded labour categories in a search index that needs no login, priced from — to — an hour. Both statements are true at once: the vendor restricts its card, and the buyer publishes the rates it awarded under it.
Why this belongs in a noise study. It does not, on its own. It is here because this comparison could not have been made from vendor disclosure alone, and a reader deciding whether to trust the numbers above should know which of them came from a firm and which came from a government.
From the client's own billing telemetry. The full derivation, and the one inference it still rests on, are in the usage dashboard.
The wall-clock span is not working time: it is the interval from the first request to the last, across three calendar days, and most of it is the human being elsewhere. Inference time is the sum of model latency and is a better lower bound on machine work than on human work. Neither is a timesheet, and no timesheet was kept.
The human hours are not measured and are not zero. Every question asked, every direction changed, every claim rejected and every withdrawal ordered came from a person. That labour is the input this page cannot price, and any ratio computed from the $236.61 alone silently sets it to zero.
python procurement/fetch_rates.py — sweeps the GSA ceiling-rate
index in price bands and writes rates.json.python procurement/fetch_awards.py — pulls federal noise-study
awards from USASpending and writes awards.json.usage-calc build — reads the local billing
store and writes usage-data.json.python procurement/build_procurement_data.py — combines all
three, applies the hours band, and injects this page.Recorded here because either one produces a plausible wrong answer with no error.
hits.total.value saturates at 10,000 and reports
relation: "gte". Taken at face value it under-counts the project
manager population by 2,913 and every percentile computed from it is wrong.page_size caps near 1,000 rows and the default ordering is price
ASCENDING. Asking for 1,000 rows of a 12,913-row population returns the thousand
cheapest, not a sample. A median taken from that slice is not a median of
anything.Both are avoided by sweeping the price axis in bands, which return exact counts, and subdividing any band the page cap cannot hold. Bands are inclusive at both ends, so rows priced exactly on a split point are returned twice and are deduplicated on the index document id.