[
 {
  "title": "Boston Globe: Boston's fire alarm boxes (2026)",
  "url": "https://www.bostonglobe.com/2026/04/03/metro/fire-alarm-boxes/",
  "type": "article",
  "topic": "boston",
  "why": "The best current account of Boston's 1852 fire alarm telegraph."
 },
 {
  "title": "Taking care of Boston's streetlights",
  "url": "https://www.boston.gov/departments/public-works/taking-care-bostons-streetlights",
  "type": "official page",
  "topic": "boston",
  "why": "Official counts of streetlights, gas lights and fire-alarm lights, plus how to report a problem."
 },
 {
  "title": "Boston PWD Sidewalk Construction and Rehabilitation Standards",
  "url": "https://www.cityofboston.gov/images_documents/sidewalk%20policy%200114_tcm3-41668.pdf",
  "type": "standard",
  "topic": "boston",
  "why": "The rules on brick, concrete, ramps and tactile strips."
 },
 {
  "title": "Freedom Trail Establishment",
  "url": "https://www.thefreedomtrail.org/node/77",
  "type": "history",
  "topic": "boston",
  "why": "The 1951 dedication, the 1958 red line and the 1972 extension."
 },
 {
  "title": "The MBTA's First Decades",
  "url": "https://www.leventhalmap.org/digital-exhibitions/getting-around-town/topics/a-period-of-newness/",
  "type": "history",
  "topic": "boston",
  "why": "Where the T logo and the color-coded map came from."
 },
 {
  "title": "Seattle DOT Traffic Control Manual: Materials and Personnel",
  "url": "https://seattle.gov/Documents/Departments/SDOT/About/DocumentLibrary/TrafficControlManual/IV.MaterialsandPersonnelforTrafficControl.pdf",
  "type": "manual",
  "topic": "work-zones",
  "why": "A plain-language digest of MUTCD Part 6 work zone devices."
 },
 {
  "title": "MUTCD Chapter 2N: Emergency Management Signing",
  "url": "https://mutcd.fhwa.dot.gov/htm/2009r1r2/part2/part2n.htm",
  "type": "standard",
  "topic": "work-zones",
  "why": "The federal spec for Evacuation Route and tsunami signs."
 },
 {
  "title": "Manitoba Hydro: What's up with those green boxes?",
  "url": "https://www.hydro.mb.ca/articles/2023/04/whats_up_with_those_green_boxes/",
  "type": "explainer",
  "topic": "work-zones",
  "why": "Practical tips for telling power boxes from telecom boxes, and how far to stay away."
 },
 {
  "title": "WA State Tsunami Wayfinding Methodology",
  "url": "https://mil.wa.gov/asset/688a5f3c80d8b/WA-State-Tsunami-Wayfinding-Methodology-V1.pdf",
  "type": "manual",
  "topic": "work-zones",
  "why": "The full tsunami sign family, with shapes, colors and sizes."
 },
 {
  "title": "Street sweeping in the City",
  "url": "https://boston.gov/node/2256",
  "type": "official page",
  "topic": "work-zones",
  "why": "Boston's sweeping seasons, towing costs and reminder sign-up."
 },
 {
  "title": "Coal holes, pavement lights, kerbs and utilities",
  "url": "https://www.designingbuildings.co.uk/wiki/Coal_hole_cover",
  "type": "reference",
  "topic": "lids-grates",
  "why": "The best single source on UK coal holes and pavement lights."
 },
 {
  "title": "Universal Hub: New England Telephone covers",
  "url": "https://universalhub.com/node/98249",
  "type": "article",
  "topic": "manhole-covers",
  "why": "A Boston cover decoder with reader additions."
 },
 {
  "title": "Forgotten New York: Gas, Water and Telephone Relics (Boston)",
  "url": "https://forgotten-ny.com/2015/06/gas-water-and-telephone-relics/amp",
  "type": "article",
  "topic": "manhole-covers",
  "why": "Photos of BWW, BCG and Bell System covers around Boston."
 },
 {
  "title": "What Are Those Grids of Glass in the Sidewalk?",
  "url": "https://www.kqed.org/news/11791667/what-are-those-grids-of-glass-in-the-sidewalk-and-why-are-they-purple",
  "type": "article",
  "topic": "lids-grates",
  "why": "Vault lights and why they turn purple."
 },
 {
  "title": "Nashua's triangular manhole covers",
  "url": "https://www.nashuatelegraph.com/news/local-news/2011/08/21/historic-and-unique-nashua-8217s-triangular-manhole-covers-are-being-replaced-because-they-8217re-too-small",
  "type": "article",
  "topic": "manhole-covers",
  "why": "The definitive story of New England's triangle covers."
 },
 {
  "title": "MLIT manhole card press release (Japanese)",
  "url": "https://www.mlit.go.jp/report/press/content/001617936.pdf",
  "type": "official",
  "topic": "manhole-covers",
  "why": "Official manhole card counts."
 },
 {
  "title": "GPO joint box and manhole covers",
  "url": "https://www.britishtelephones.com/gpo/jointbox3.htm",
  "type": "reference",
  "topic": "manhole-covers",
  "why": "UK telecom cover types and dates."
 },
 {
  "title": "BWSC Storm Drain Marking",
  "url": "https://www.bwsc.org/environment-education/teachers-students/storm-drain-marking",
  "type": "official",
  "topic": "lids-grates",
  "why": "Boston's Don't Dump program."
 },
 {
  "title": "THE CITY: manhole explosion season",
  "url": "https://www.thecity.nyc/2020/02/24/it-s-manhole-explosion-season-what-you-need-to-know-about-a-century-old-problem/",
  "type": "article",
  "topic": "manhole-covers",
  "why": "Causes and numbers behind New York's manhole fires."
 },
 {
  "title": "US Access Board: Detectable Warnings Update",
  "url": "https://www.access-board.gov/prowag/detectable-warnings-update.html",
  "type": "guidance",
  "topic": "curbs",
  "why": "The federal explanation of where truncated domes are and are not required."
 },
 {
  "title": "2010 ADA Standards 705",
  "url": "https://www.corada.com/documents/2010ADAStandards/705-1",
  "type": "standard",
  "topic": "curbs",
  "why": "The dome dimensions and contrast rule in the original text."
 },
 {
  "title": "Penn State LTAP: Overview of the Finalized PROWAG",
  "url": "https://www.tesc.psu.edu/assets/docs/An-Overview-of-the-Finalized-Public-Rights-of-Way-Accessibility-Guidelines.pdf",
  "type": "guide",
  "topic": "curbs",
  "why": "A plain summary of the 2023 public right-of-way rule."
 },
 {
  "title": "UK DfT: Guidance on the use of tactile paving surfaces",
  "url": "https://assets.publishing.service.gov.uk/media/61df0c91e90e07037794fe90/guidance-on-the-use-of-tactile-paving-surfaces.pdf",
  "type": "guidance",
  "topic": "curbs",
  "why": "The definitive UK reference with diagrams of every surface."
 },
 {
  "title": "Japan Up Close: Tenji blocks",
  "url": "https://japanupclose.web-japan.org/tech/t20211008_1.html",
  "type": "article",
  "topic": "curbs",
  "why": "The origin story and why the blocks turned yellow."
 },
 {
  "title": "California Vehicle Code 21458",
  "url": "https://california.public.law/codes/vehicle_code_section_21458",
  "type": "law",
  "topic": "curbs",
  "why": "The curb color statute itself."
 },
 {
  "title": "Living New Deal: Sidewalks and Stairs",
  "url": "https://livingnewdeal.org/new-deal-categories/sidewalks-and-stairs",
  "type": "database",
  "topic": "sidewalks",
  "why": "A map and database of surviving WPA sidewalk stamps."
 },
 {
  "title": "City of Boston: Public vs. private ways",
  "url": "https://www.boston.gov/departments/public-works/public-vs-private-ways",
  "type": "guide",
  "topic": "sidewalks",
  "why": "Who maintains, plows and polices a Boston street."
 },
 {
  "title": "The Proper Painting of Fire Hydrants (Mueller Co.)",
  "url": "https://www.muellercompany.com/sites/muellercompany.com/files/uploads/media/mueller_wp17303_paintingfirehydrants_f13807_v8.pdf",
  "type": "white paper",
  "topic": "hydrants",
  "why": "The clearest summary of the NFPA 291 color classes and body colors."
 },
 {
  "title": "Fire hydrant (Wikipedia)",
  "url": "https://en.wikipedia.org/wiki/Fire_hydrant",
  "type": "encyclopedia",
  "topic": "hydrants",
  "why": "A wide global overview, including UK, German and Australian marking systems."
 },
 {
  "title": "Fire Hydrant Plates (Essex County Fire and Rescue)",
  "url": "https://www.essex-fire.gov.uk/fire-hydrant-plates",
  "type": "official guide",
  "topic": "hydrants",
  "why": "How to read the UK yellow H plate and where its design came from."
 },
 {
  "title": "Fire Hydrants dataset (Analyze Boston)",
  "url": "https://data.boston.gov/dataset/1f43041c-e2ff-4784-b537-3ecb7ceae066",
  "type": "open data",
  "topic": "hydrants",
  "why": "Map and download every public hydrant BWSC maintains in Boston."
 },
 {
  "title": "Adopt-A-Hydrant (City of Boston)",
  "url": "https://www.boston.gov/departments/new-urban-mechanics/adopt-hydrant",
  "type": "city program",
  "topic": "hydrants",
  "why": "Claim a Boston hydrant and commit to shoveling it out after storms."
 },
 {
  "title": "Understanding Fire Department Connection Sign Requirements (NFSA)",
  "url": "https://nfsa.org/?p=16658",
  "type": "industry article",
  "topic": "fire-hardware",
  "why": "What AUTOSPKR, STANDPIPE and pressure signs on FDCs mean."
 },
 {
  "title": "How Does a Water Motor Gong Work? (QRFS)",
  "url": "https://blog.qrfs.com/360-how-does-a-water-motor-gong-work-in-fire-sprinkler-systems/",
  "type": "industry article",
  "topic": "fire-hardware",
  "why": "A clear explanation of the outdoor sprinkler bell, with the code rules."
 },
 {
  "title": "Fire Alarm Hardware (Boston Fire Historical Society)",
  "url": "https://bostonfirehistory.org/fire-alarm/hardware/",
  "type": "history",
  "topic": "fire-hardware",
  "why": "Photos and details of Boston's fire alarm boxes, lamps and circuits."
 },
 {
  "title": "Regulator safety flyer (National Grid)",
  "url": "https://outreach.ngridsafety.com/wp-content/uploads/2022/04/13036_95595_NGrid_FR_ToT_Regulators_flyer_ng_0222.pdf",
  "type": "utility guide",
  "topic": "fire-hardware",
  "why": "Why gas regulator vents must stay clear and who may operate gas valves."
 },
 {
  "title": "MUTCD 11th Edition, Part 3: Markings",
  "url": "https://mutcd.fhwa.dot.gov/pdfs/11th_Edition/part3.pdf",
  "type": "standard",
  "topic": "road-lines",
  "why": "The US rulebook for marking colors, widths, words, stop lines and crosswalks."
 },
 {
  "title": "FHWA MUTCD Interim Approvals",
  "url": "https://mutcd.fhwa.dot.gov/res-interim_approvals.htm",
  "type": "official list",
  "topic": "crosswalks",
  "why": "Dates and status of the approvals behind green bike lanes, bike boxes, turn boxes and red bus lanes."
 },
 {
  "title": "NACTO MUTCD Webinar 5: Bikes",
  "url": "https://nacto.org/wp-content/uploads/2024-1030-NACTO-MUTCD-Webinar-5-Bikes.pdf",
  "type": "slide deck",
  "topic": "crosswalks",
  "why": "Plain summary of the 11th edition's bike marking rules."
 },
 {
  "title": "MUTCD marking color evolution",
  "url": "https://ghawkins.engr.tamu.edu/wp-content/uploads/sites/242/2021/08/MUTCDmarkingcolorevolution.pdf",
  "type": "history",
  "topic": "road-lines",
  "why": "How US center lines went from white, yellow or black to yellow."
 },
 {
  "title": "PBIC: Crossings and Crosswalks",
  "url": "https://www.walkinginfo.org/engineering/crossings-crosswalks/",
  "type": "guide",
  "topic": "crosswalks",
  "why": "Why and how crosswalks are marked, with costs and safety guidance."
 },
 {
  "title": "The Highway Code: Road markings",
  "url": "https://www.gov.uk/guidance/the-highway-code/road-markings",
  "type": "official guide",
  "topic": "crosswalks",
  "why": "UK meanings of lines, curb markings and crossings on one page."
 },
 {
  "title": "SABRE: Pedestrian Crossings, Black and White",
  "url": "https://www.roads.org.uk/articles/pedestrian-crossings/black-and-white",
  "type": "history",
  "topic": "crosswalks",
  "why": "History of the UK zebra crossing and Belisha beacon."
 },
 {
  "title": "99% Invisible: End of the Road for Botts' Dots",
  "url": "https://99percentinvisible.org/article/end-road-botts-dots-round-markers-phased-california/",
  "type": "article",
  "topic": "road-lines",
  "why": "Readable history of California's raised dots."
 },
 {
  "title": "FHWA Rumble Strips: General Information",
  "url": "https://highways.fhwa.dot.gov/safety/keep-vehicles-road/rumble-strips/general-information",
  "type": "official guide",
  "topic": "road-lines",
  "why": "Types of rumble strips and their crash reductions."
 },
 {
  "title": "FHWA Traffic Detector Handbook, ch. 2",
  "url": "https://www.fhwa.dot.gov/publications/research/operations/its/06108/02.cfm",
  "type": "technical handbook",
  "topic": "road-lines",
  "why": "Explains the loop saw cuts at signalized intersections."
 },
 {
  "title": "CGA Best Practices, Appendix B",
  "url": "https://bestpractices.commongroundalliance.com/Appendix-B-Uniform-Color-Code-and-Marking-Guide",
  "type": "reference",
  "topic": "paint",
  "why": "The official US marking guide: colors, abbreviations, delineation and tolerance zone."
 },
 {
  "title": "About Dig Safe (Mass.gov)",
  "url": "https://www.mass.gov/guides/about-dig-safe",
  "type": "guide",
  "topic": "paint",
  "why": "Massachusetts dig rules, ticket life and penalties in plain language."
 },
 {
  "title": "Dig Safe FAQs",
  "url": "https://www.digsafe.com/faqs",
  "type": "guide",
  "topic": "paint",
  "why": "New England one-call center, with ticket lifetimes for each state."
 },
 {
  "title": "Virginia Marking Standards Manual",
  "url": "https://scc.virginia.gov/urs/manuals/markingstandardsmanual/index.html",
  "type": "manual",
  "topic": "paint",
  "why": "A detailed state field manual with symbols such as offsets and humps."
 },
 {
  "title": "LinesearchbeforeUdig",
  "url": "https://lsbud.co.uk/linesearchbeforeudig-users/",
  "type": "tool",
  "topic": "paint",
  "why": "The UK's free online search of buried asset owners."
 },
 {
  "title": "Before You Dig Australia",
  "url": "https://www.byda.com.au/about/what-we-do/",
  "type": "tool",
  "topic": "paint",
  "why": "Australia's free national plan referral service."
 },
 {
  "title": "NGS Survey Mark Recovery",
  "url": "https://geodesy.noaa.gov/surveys/mark-recovery/",
  "type": "tool",
  "topic": "survey-marks",
  "why": "How to report a survey mark you have found."
 },
 {
  "title": "NOAA survey mark hunting activity",
  "url": "https://www.nauticalcharts.noaa.gov/learn/docs/educational-activities/survey-mark-hunting.pdf",
  "type": "guide",
  "topic": "survey-marks",
  "why": "Beginner walkthrough of finding a datasheet and a mark."
 },
 {
  "title": "Ordnance Survey benchmarks",
  "url": "https://www.ordnancesurvey.co.uk/benchmarks/",
  "type": "database",
  "topic": "survey-marks",
  "why": "Search and download Britain's benchmark archive."
 },
 {
  "title": "Benchmark Types (Rushden Heritage)",
  "url": "https://www.rushdenheartsandsoles.co.uk/history/Benchmark-Types.html",
  "type": "guide",
  "topic": "survey-marks",
  "why": "Illustrated guide to UK cut marks, rivets, bolts and flush brackets."
 },
 {
  "title": "FHWA: Backplates with Retroreflective Borders",
  "url": "https://highways.dot.gov/safety/proven-safety-countermeasures/backplates-retroreflective-borders",
  "type": "government",
  "topic": "signal-gear",
  "why": "Official one-page summary with the crash-reduction figure."
 },
 {
  "title": "IKE GPS: Communication worker safety zone",
  "url": "https://ikegps.com/ikewire/communication-worker-safety-zone",
  "type": "industry explainer",
  "topic": "utility-poles",
  "why": "Plain-English guide to the NESC gap between power and telecom."
 },
 {
  "title": "Ameren: Utility Pole Assessment",
  "url": "https://www.ameren.com/-/media/corporate-site/Files/SafetyPartners/UtilityPoleAssessment.pdf",
  "type": "utility guide (PDF)",
  "topic": "utility-poles",
  "why": "Photos and examples of pole brands and tags."
 },
 {
  "title": "EC&M: Look, fiber optics above you",
  "url": "https://www.ecmag.com/section/systems/look-fiber-optics-above-you",
  "type": "trade article",
  "topic": "utility-poles",
  "why": "A field guide to aerial telecom cables, closures and snowshoes."
 },
 {
  "title": "PBIC: Accessible Pedestrian Signals",
  "url": "https://www.walkinginfo.org/aps/5-4",
  "type": "reference guide",
  "topic": "signal-gear",
  "why": "The standard reference on APS features."
 },
 {
  "title": "KQED: Why do some crosswalks make a machine-gun sound?",
  "url": "https://www.kqed.org/news/11795009/why-do-some-crosswalks-make-a-machine-gun-sound",
  "type": "news explainer",
  "topic": "signal-gear",
  "why": "Accessible explainer on the rapid-tick walk signal."
 },
 {
  "title": "FHWA: Safety Effectiveness of the HAWK",
  "url": "https://www.fhwa.dot.gov/publications/research/safety/pedbike/11039/008.cfm",
  "type": "government research",
  "topic": "signal-gear",
  "why": "The original Tucson crash study."
 },
 {
  "title": "DDR Museum: the Ampelmännchen",
  "url": "https://www.ddr-museum.de/en/blog/archive/what-remains-gdr-part-v-traffic-signs-ampelmaennchen",
  "type": "museum article",
  "topic": "signal-gear",
  "why": "History of the East German walking man from a Berlin museum."
 },
 {
  "title": "City of Bloomington, MN: Traffic signal detection",
  "url": "https://www.bloomingtonmn.gov/node/5986",
  "type": "government",
  "topic": "signal-gear",
  "why": "Plain explanation of loops and detection cameras."
 },
 {
  "title": "FHWA MUTCD home",
  "url": "https://mutcd.fhwa.dot.gov/index.htm",
  "type": "official",
  "topic": "signs",
  "why": "The official US manual for signs, now the 11th edition with Revision 1."
 },
 {
  "title": "trafficsign.us: Sign color",
  "url": "https://www.trafficsign.us/signcolor.html",
  "type": "reference",
  "topic": "signs",
  "why": "A concise table of what each US sign color means."
 },
 {
  "title": "Signalfan.com: Stop sign history",
  "url": "https://signalfan.com/road%20signs/stopsign.htm",
  "type": "history",
  "topic": "signs",
  "why": "Year-by-year evolution of the US stop sign."
 },
 {
  "title": "NPR: Los Angeles' new parking signs",
  "url": "https://www.npr.org/sections/thetwo-way/2015/04/06/397858800/how-do-you-like-los-angeles-new-parking-signs",
  "type": "article",
  "topic": "signs",
  "why": "The grid design meant to untangle parking sign stacks."
 },
 {
  "title": "FHWA: Interstate shields and signs",
  "url": "https://highways.dot.gov/history/interstate-system/50th-anniversary/shields-and-signs",
  "type": "history",
  "topic": "sign-codes",
  "why": "How the shield and green guide signs were chosen."
 },
 {
  "title": "FHWA: Minimum sign retroreflectivity",
  "url": "https://highways.dot.gov/safety/other/visibility/minimum-sign-retroreflectivity-requirements",
  "type": "official",
  "topic": "sign-codes",
  "why": "Why and when signs get replaced."
 },
 {
  "title": "FHWA: Clearview report to Congress",
  "url": "https://mutcd.fhwa.dot.gov/resources/interim_approval/ia5rptcongress/exec_summary.htm",
  "type": "official",
  "topic": "sign-codes",
  "why": "FHWA's own account of the Clearview font dispute."
 },
 {
  "title": "TxDOT: Sign identification decal",
  "url": "https://www.txdot.gov/manuals/trf/smk/sign_materials_and_supports/sign_id_decal-i1019387.html",
  "type": "official",
  "topic": "sign-codes",
  "why": "How to read a punch-coded label on the back of a sign."
 },
 {
  "title": "Design Week: 50 years of Calvert and Kinneir's road signs",
  "url": "https://www.designweek.co.uk/50-years-of-calvert-kinneirs-road-signs/",
  "type": "article",
  "topic": "sign-codes",
  "why": "The story of the UK sign system and its designers."
 },
 {
  "title": "Wikipedia: Vienna Convention on Road Signs and Signals",
  "url": "https://en.wikipedia.org/wiki/Vienna_Convention_on_Road_Signs_and_Signals",
  "type": "reference",
  "topic": "sign-codes",
  "why": "Sign categories used across Europe and beyond."
 }
]