clm-a7d9ed76e73ce1fa
quantitative
Boston's New Urban Mechanics office started Street Bump in 2011 and put the public version out in 2012
Permanent project revision
Revision 2026-08-20-claim-baseline · effective 2026-07-26
Superseded. A later revision exists: 2026-08-21-source-dates →
Created the first structured Evidence Passport with 8 claims and 11 source dossiers.
sha256:69883d2fcfb388747b71dc24ddf9b0fbb025408fed03af5e7307a625d16b05b4
add /evidencePassport — Added claim-level evidence mapping and source dossiers.add /revisionHistory — Established a permanent, hash-addressed baseline revision.The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.
clm-a7d9ed76e73ce1fa
quantitative
Boston's New Urban Mechanics office started Street Bump in 2011 and put the public version out in 2012
clm-ba4c49c4726d851e
descriptive
an app that read a driving phone's accelerometer and GPS and filed road defects without anyone tapping anything
clm-735e8a3b5c4200c9
descriptive
Its biggest finding was not potholes but sunken manhole covers
clm-fb7e02ba229c13a6
quantitative
The city ended the project in 2014
clm-17e20d1f4eb8ece6
quantitative
The city reports that sunken manhole covers caused about four times more bumps than potholes, that it fixed 1,250 of the worst covers by working with the utilities that own them, and that testing held false positives under 10%
clm-2b163f319872cd68
descriptive
Boston never published how many reports the app generated, how many were confirmed, or whether repairs got faster
clm-37b1856b6d20c8cd
quantitative
Kate Crawford's 2013 Harvard Business Review essay made Street Bump the standard example of a sensing system's 'signal problem': a phone-and-car sensor samples people who own phones and cars
clm-66150ef40dcf9372
descriptive
That was an argument from smartphone ownership, not a measurement of Street Bump's own reports — Boston never published a neighbourhood breakdown, so the most-cited critique in civic sensing was never tested against the data it describes
This layer records what is known about each source, what is still missing, and the exact snapshot this page is rendering. A missing date, archive or hash stays visible as missing.
Awaiting operator and domain-expert review; publication of this revision implies neither.
sha256:69883d2fcfb388747b71dc24ddf9b0fbb025408fed03af5e7307a625d16b05b4
src-8a8315485119ded3The operator's own page and the authority for the load-bearing facts. Status, sentence-level: 'The involvement of New Urban Mechanics in this project was from 2011 to 2014. The project is not currently active.' Also the three phases (2011 alpha, the public algorithm competition, the 2012 accelerometer-and-GPS release), the finding 'Residents most frequently reported problems about potholes, but the biggest cause of bumps is sunk manhole covers' at roughly four times the rate, the 1,250 covers fixed with the utilities, 'false positives under 10%', and the partner list: Fabio Carrera, Red Fish Group, IDEO, Connected Bits, InnoCentive and Boston University researchers. No statement of why the project ended appears anywhere.
src-8470dc136a3b9792Independent account of the mechanism and the aggregation rule: the phone sends accelerometer data to a server that combines many phones, and 'If at least three people hit a bump in the same spot, the system recognizes it as a pothole.' Names Nigel Jacob of New Urban Mechanics as project lead and states the city's hope of replacing survey trucks with a real-time map.
src-efba295fd7e79df6Local public-radio coverage of the 2012 public release, used as the second source for the launch year.
src-d9389d8839e144f0Contemporary account of the algorithm competition: after the first build could not tell potholes from other bumps and produced too many false positives, the city turned to InnoCentive, with $25,000 in prize money donated by Liberty Mutual. The contest drew more than 700 solvers and 19 submitted solutions.
src-5247cec9c3bf8a8cA winning entry, from the winners' own institutional record: three winning teams were announced in December, two of them awarded $9,000 each. The method was wavelet analysis and Kruskal's algorithm — signal processing, not machine learning, which is why this entry carries ai: false.
src-60cc2fcbe258dab6Contemporary independent press on the manhole-cover finding. The Globe paywall blocks automated fetch; the outlet, date and subject were confirmed by search, and the substance is carried sentence-level by the city page above.
src-57f3dd7e678eeb9cThe origin of the critique, and the reason for the lesson's careful wording. This is a business-magazine essay, NOT a peer-reviewed paper: Crawford writes that 'StreetBump has a signal problem' because lower-income and older residents are less likely to own smartphones. The argument is drawn from smartphone-ownership demographics; neither this piece nor any source found analyses Street Bump's own reports by neighbourhood. HBR is paywalled to automated fetch; the passage is reproduced by the textbook below.
src-e11fe8f03da13ba1Carries Crawford's Street Bump passage verbatim and shows how the case entered the algorithmic-fairness canon: 'Consider Street Bump, a project by the city of Boston to crowdsource data on potholes' … the data reflect 'the patterns of smartphone ownership, which are higher in wealthier parts of the city compared to lower-income areas and areas with large elderly populations.' The textbook presents it as an observation about the method, with no measurement of the project's data.
src-71bfb24de52b4587The closest thing found to a documented Boston response: the FTC uses Street Bump as its worked example of a 'data desert', stating that once the team recognised that lower-income residents were less likely to carry smartphones, it recognised its data was not representative of road conditions across Boston. The report PDF resisted text extraction, so this is verified at search level only and is not quoted as the city's own words anywhere in this entry.
src-20be4dee91740ccbConfirms that the pre-release version was run on city inspectors' vehicles before public release, and describes the pipeline: data to Connected Bits' servers, likely problems submitted to the city through Open311 and classified as potholes to fix or known obstacles such as speed bumps.
src-b949a0b6729e13bfWhat came after, from the same offices. The Analytics Team and New Urban Mechanics tested anonymised Mercedes-Benz vehicle sensor data against 311 reports and found it 'particularly helpful for identifying potential potholes on larger streets with higher speed limits, where 311 reports are relatively rare' — passive sensing used explicitly to cover what the complaint channel misses. It also repeated Street Bump's classification problem: 'other types of irregularities in the road were getting picked up, such as depressions near utility covers.' The page does not mention Street Bump, so no lineage is claimed as fact.