{ "standard": "FactUnion Standard v1", "checkedAt": "2026-10-19T05:29:44.539Z", "title": "The Line That Vanishes in the Rain", "date": "2026-10-19", "facts": [ { "n": 1, "claim": "The Standard, as FHWA presented it in Section 3A.03 of 2009 MUTCD Revision 3, reads: 'Except as provided in Paragraph 5, a method designed to maintain retroreflectivity at or above 50 mcd/m2/lx under dry conditions shall be used for longitudinal markings on roadways with speed limits of 35 mph or greater.'", "sources": [ { "url": "https://mutcd-dr.fhwa.dot.gov/htm/2009r1r2/part3/part3a.htm", "title": "MUTCD 2009 Edition" }, { "url": "https://or-oaces.org/fhwa-final-rule-minimum-levels-for-retroreflective-pavement-markings/", "title": "FHWA Final Rule: Minimum Levels for Retroreflective Pavement Markings" } ], "verdict": "corrected", "note": "Source corrected: the page first cited was read and is about something else; the sources listed state this.", "quote": false, "usedInEpisode": true }, { "n": 2, "claim": "The rule's Guidance says a method that maintains at least 100 mcd/m2/lx under dry conditions should be used on roadways with speed limits of 70 mph or greater. This is a recommendation, not a mandate.", "sources": [ { "url": "https://mutcd-dr.fhwa.dot.gov/htm/2009r1r2/part3/part3a.htm", "title": "MUTCD 2009 Edition" }, { "url": "https://www.lexfed.com/federal-register/2022-16781", "title": "National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for Streets and Highways; Maintaining Pavement Marking Retroreflectivity" }, { "url": "https://or-oaces.org/fhwa-final-rule-minimum-levels-for-retroreflective-pavement-markings/", "title": "FHWA Final Rule: Minimum Levels for Retroreflective Pavement Markings" } ], "verdict": "corrected", "note": "Source corrected: the page first cited was read and is about something else; the sources listed state this.", "quote": false, "usedInEpisode": true }, { "n": 3, "claim": "Agencies may exclude several categories from the 3A.05 minimum: roads with ADT below 6,000 vehicles per day, markings kept visible by ambient illumination, dotted extension lines, curb markings, parking space markings and shared-use path markings.", "sources": [ { "url": "https://mutcd-dr.fhwa.dot.gov/htm/2009r1r2/part3/part3a.htm", "title": "MUTCD 2009 Edition" }, { "url": "https://buildspec.codes/codes/mutcd/3a.05", "title": "MUTCD 3A.05: Maintaining Minimum Pavement Marking…" }, { "url": "https://www.mutcd.fyi/az/2026/part-3a-general/", "title": "Arizona MUTCD 2026 §3A: Markings, General" } ], "verdict": "corrected", "note": "Source corrected: the page first cited was read and is about something else; the sources listed state this.", "quote": false, "usedInEpisode": true }, { "n": 4, "claim": "The minimum applies only to longitudinal markings. Transverse markings, word, symbol and arrow markings, crosswalks, and chevron, diagonal and crosshatch markings are excluded.", "sources": [ { "url": "https://mutcd-dr.fhwa.dot.gov/htm/2009r1r2/part3/part3a.htm", "title": "MUTCD 2009 Edition" }, { "url": "https://buildspec.codes/codes/mutcd/3a.05", "title": "MUTCD 3A.05: Maintaining Minimum Pavement Marking…" }, { "url": "https://retrotekusa.com/mandatory-minimum-retroreflectivity-standards-for-pavement-markings-on-us-roads/", "title": "Mandatory Minimum Pavement Marking Retroreflectivity Standards for US Roads" } ], "verdict": "corrected", "note": "Source corrected: the page first cited was read and is about something else; the sources listed state this.", "quote": false, "usedInEpisode": true }, { "n": 5, "claim": "FHWA published the pavement-marking retroreflectivity final rule on 5 August 2022, effective 6 September 2022, and the 11th edition of the MUTCD (19 December 2023) carried it into Section 3A.05.", "sources": [ { "url": "https://highways.dot.gov/safety/other/visibility/pavement-markings-regulations-standards", "title": "Pavement Markings Regulations / Standards" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 6, "claim": "The final rule, effective 6 September 2022, requires agencies to implement a method for maintaining pavement-marking retroreflectivity at or above the minimum levels and gives them a 4-year compliance date to do so.", "sources": [ { "url": "https://www.govinfo.gov/content/pkg/FR-2022-08-05/html/2022-16781.htm", "title": "Federal Register, Volume 87 Issue 150 (Friday, August 5, 2022)" }, { "url": "https://doi.org/10.1177/03611981241287196", "title": "Development of a Machine-Learning-Based Tool to Predict Retroreflectivity of Pavement Markings Across the U.S. - Ipshit Ibne Idris, Momen Mousa, Marwa Hassan, Paul Carlson, Eric Greyson, 2025" }, { "url": "https://www.kittelsonllc.com/an-important-mutcd-update/", "title": "An Important MUTCD Update" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 7, "claim": "3M defines the effect this way: 'Retroreflection occurs when a surface returns a large portion of directed light beam back to its source.'", "sources": [ { "url": "https://www.3m.com/3M/en_US/road-safety-us/resources/road-transportation-safety-center-blog/full-story/~/road-signs-retroreflectivity/?storyid=328c8880-941b-4adc-a9f9-46a1cd79e637", "title": "What is retroreflectivity & why is it important?" }, { "url": "https://www.3mphilippines.com.ph/3M/en_PH/road-safety-ph/resources/road-transportation-safety-center-blog/full-story/~/road-signs-retroreflectivity/?storyid=a21d2fd4-b12f-4e77-84fb-5160c9c5579a", "title": "What is retroreflectivity & why is it important?" }, { "url": "https://www.3mindia.in/3M/en_IN/road-safety-in/resources/road-transportation-safety-center-blog/full-story/~/road-signs-retroreflectivity/?storyid=a4856606-b4b0-430e-900a-b6866cbaeadb", "title": "What Is Retroreflectivity & Why Is It Important? | 3M India" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 8, "claim": "3M explains that in a glass bead the incoming light bends, reflects off a mirrored surface behind the bead, bends again and returns toward the light source. It also says large trucks can have twice the observation angle of passenger cars at the same distance, which makes retroreflective surfaces look dimmer.", "sources": [ { "url": "https://www.3m.com/3M/en_US/road-safety-us/resources/road-transportation-safety-center-blog/full-story/~/road-signs-retroreflectivity/?storyid=328c8880-941b-4adc-a9f9-46a1cd79e637", "title": "What is retroreflectivity & why is it important?" }, { "url": "https://www.3mindia.in/3M/en_IN/road-safety-in/resources/road-transportation-safety-center-blog/full-story/~/road-signs-retroreflectivity/?storyid=a4856606-b4b0-430e-900a-b6866cbaeadb", "title": "What Is Retroreflectivity & Why Is It Important? | 3M India" }, { "url": "https://www.3mphilippines.com.ph/3M/en_PH/road-safety-ph/resources/road-transportation-safety-center-blog/full-story/~/road-signs-retroreflectivity/?storyid=a21d2fd4-b12f-4e77-84fb-5160c9c5579a", "title": "What is retroreflectivity & why is it important?" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 9, "claim": "TTI and 3M researchers wrote that 'a layer of water refracts the light differently than air, causing conventional markings to substantially retroreflect the light away from the driver or camera when the marking is immersed.'", "sources": [ { "url": "https://saemobilus.sae.org/papers/effects-wet-retroreflectivity-luminance-pavement-markings-lane-departure-warning-nighttime-continuous-rain-without-glare-sources-2019-01-1014", "title": "2019-01-1014: Effects of the Wet Retroreflectivity and Luminance of Pavement Markings on Lane Departure Warning in Nighttime Continuous Rain with and without Glare Sources" }, { "url": "https://trid.trb.org/view/1598911", "title": "Effects of the Wet Retroreflectivity and Luminance of Pavement Markings on Lane Departure Warning in Nighttime Continuous Rain with and without Glare Sources" }, { "url": "https://www.tib.eu/de/suchen/id/sae:21d5a5ef96a1187e70c4a2a8f582702834cc234a", "title": "Effects of the Wet Retroreflectivity and Luminance of Pavement Markings on Lane Departure Warning in Nighttime Continuous Rain with and without Glare SourcesIcon MastodonIcon InstagramIcon LinkedinIco" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 10, "claim": "A 2004 Virginia report attributed wet-night degradation to 'the flooding of the marking optics, thereby reducing retroreflectivity.'", "sources": [ { "url": "https://rosap.ntl.bts.gov/view/dot/19652", "title": "DOT ROSA P" }, { "url": "https://vtrc.virginia.gov/reports/all-reports/05-cr3/", "title": "Virginia Transportation Research Council" }, { "url": "https://vtechworks.lib.vt.edu/items/948d0437-93a4-49bf-8fef-ba454b5494f7", "title": "VTechWorks Home" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 11, "claim": "The 2009 closed-course study 'Nighttime Visibility of Prototype Work Zone Markings under Dry, Wet-Recovery, and Rain Conditions' was written by Laura Higgins, Jeffrey D. Miles, Paul Carlson, David Burns, Fuat Aktan, Mark Zender and James M. Kaczmarczik. Its authors were from the Texas Transportation Institute and 3M, and it was conducted under FHWA's Highways for LIFE Technology Partnerships Program.", "sources": [ { "url": "https://doi.org/10.3141/2107-07", "title": "Nighttime Visibility of Prototype Work Zone Markings under Dry, Wet-Recovery, and Rain Conditions - Laura Higgins, Jeffrey D. Miles, Paul Carlson, David Burns, Fuat Aktan, Mark Zender, James M. Kaczma" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 12, "claim": "In that study, 30 participants drove through simulated work zones at night and identified the direction of lane-shift tapers marked by each marking type, under dry, wet-recovery and rain conditions.", "sources": [ { "url": "https://doi.org/10.3141/2107-07", "title": "Nighttime Visibility of Prototype Work Zone Markings under Dry, Wet-Recovery, and Rain Conditions - Laura Higgins, Jeffrey D. Miles, Paul Carlson, David Burns, Fuat Aktan, Mark Zender, James M. Kaczma" }, { "url": "https://highways.dot.gov/safety/other/visibility/synthesis-pavement-marking-research/chapter-5-wet-pavement-marking", "title": "Chapter 5: Wet Pavement Marking Retroreflectivity | FHWA" }, { "url": "https://trid.trb.org/view/881522", "title": "TRIDNational Academies of Sciences, Engineering, and MedicineTransportation Research BoardNational Academies of Sciences, Engineering, and Medicine" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 13, "claim": "Detection distances for the conventional glass beads-on-paint benchmark 'dropped to 28% and 17% of the dry detection distance, respectively' in wet-recovery and rain, and participants 'failed to detect the conventional glass beads-on-paint benchmark system in nearly half of the observations in the rain condition.'", "sources": [ { "url": "https://doi.org/10.3141/2107-07", "title": "Nighttime Visibility of Prototype Work Zone Markings under Dry, Wet-Recovery, and Rain Conditions - Laura Higgins, Jeffrey D. Miles, Paul Carlson, David Burns, Fuat Aktan, Mark Zender, James M. Kaczma" }, { "url": "https://trid.trb.org/view/881522", "title": "TRIDNational Academies of Sciences, Engineering, and MedicineTransportation Research BoardNational Academies of Sciences, Engineering, and Medicine" }, { "url": "https://workzonesafety.org/publication/nighttime-visibility-of-prototype-work-zone-markings-under-dry-wet-recovery-and-rain-conditions/", "title": "Nighttime Visibility of Prototype Work Zone Markings Under Dry, Wet-Recovery, and Rain Conditions" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 14, "claim": "The three high-refractive-index dual-optics prototypes and a wet-reflective tape kept 60 to 80% of their dry detection distance in wet-recovery and 50 to 70% in rain.", "sources": [ { "url": "https://doi.org/10.3141/2107-07", "title": "Nighttime Visibility of Prototype Work Zone Markings under Dry, Wet-Recovery, and Rain Conditions - Laura Higgins, Jeffrey D. Miles, Paul Carlson, David Burns, Fuat Aktan, Mark Zender, James M. Kaczma" }, { "url": "https://www.fhwa.dot.gov/hfl/partnerships/all_weather_pavement/phase1/chap03.cfm", "title": "Temporary Wet-weather Pavement Markings for Mork Zones" }, { "url": "https://trid.trb.org/view/881522", "title": "TRIDNational Academies of Sciences, Engineering, and MedicineTransportation Research BoardNational Academies of Sciences, Engineering, and Medicine" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 15, "claim": "FHWA's research synthesis states that dry retroreflectivity is typically higher than wet retroreflectivity and that wet retroreflectivity cannot be predicted from dry retroreflectivity.", "sources": [ { "url": "https://highways.dot.gov/safety/other/visibility/synthesis-pavement-marking-research/chapter-5-wet-pavement-marking", "title": "Chapter 5: Wet Pavement Marking Retroreflectivity | FHWA" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 16, "claim": "FHWA's synthesis records 'concerns that increased visibility of markings in wet conditions could potentially result in more drivers going too fast for the wet conditions.'", "sources": [ { "url": "https://highways.dot.gov/safety/other/visibility/synthesis-pavement-marking-research/chapter-5-wet-pavement-marking", "title": "Chapter 5: Wet Pavement Marking Retroreflectivity | FHWA" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 17, "claim": "FHWA's synthesis reports that a 2012 Virginia study saw wet performance fall to 100 mcd/m²/lx or less after the first year, and that the study derived a minimum wet level of 150 mcd/m²/lx.", "sources": [ { "url": "https://highways.dot.gov/safety/other/visibility/synthesis-pavement-marking-research/chapter-5-wet-pavement-marking", "title": "Chapter 5: Wet Pavement Marking Retroreflectivity | FHWA" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 18, "claim": "The ASTM E2176 continuous-wetting test required almost 10 inches of water per hour, while its replacement, E2832, uses 2 inches per hour.", "sources": [ { "url": "https://highways.dot.gov/safety/other/visibility/synthesis-pavement-marking-research/chapter-5-wet-pavement-marking", "title": "Chapter 5: Wet Pavement Marking Retroreflectivity | FHWA" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 19, "claim": "Adam Pike, Gene Hawkins and Paul Carlson (2007) analysed 20 years of Texas rainfall data. They found that 88% of rainfall events had maximum rates under 0.75 in/h, while E2176 allowed 6 to 14 in/h, and that cross slope had a major impact on wet readings.", "sources": [ { "url": "https://doi.org/10.3141/2015-10", "title": "Evaluating the Retroreflectivity of Pavement Marking Materials under Continuous Wetting Conditions - Adam M. Pike, H. Gene Hawkins, Paul J. Carlson, 2007" }, { "url": "https://journals.sagepub.com/doi/full/10.3141/2015-10", "title": "Evaluating the Retroreflectivity of Pavement Marking Materials under Continuous Wetting Conditions - Adam M. Pike, H. Gene Hawkins, Paul J. Carlson, 2007" }, { "url": "https://trid.trb.org/view/801767", "title": "TRIDNational Academies of Sciences, Engineering, and MedicineTransportation Research BoardNational Academies of Sciences, Engineering, and Medicine" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 20, "claim": "A 2007 Texas study cited by FHWA found that wet-night markings are not a replacement for raised retroreflective pavement markers in visibility or in cost of visibility per mile.", "sources": [ { "url": "https://highways.dot.gov/safety/other/visibility/synthesis-pavement-marking-research/chapter-5-wet-pavement-marking", "title": "Chapter 5: Wet Pavement Marking Retroreflectivity | FHWA" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 21, "claim": "Work on retroreflectivity standards in the United States was significantly accelerated in 1984 when the Center for Auto Safety petitioned the Federal Highway Administration (FHWA) to establish retroreflectivity standards for signs and markings.", "sources": [ { "url": "https://www.fhwa.dot.gov/publications/research/safety/03081/summary.cfm", "title": "Updated Minimum Retroreflectivity Levels" } ], "verdict": "corrected", "note": "Dropped the unsupported Carlson and Hawkins attribution and \"minimum.\" Three sources support 1984, though one US Congress source gives 1985.", "quote": false, "usedInEpisode": true }, { "n": 22, "claim": "A 2016 paper says the federal rule on minimum traffic sign retroreflectivity was incorporated in the 2009 MUTCD.", "sources": [ { "url": "https://www.sciencedirect.com/science/article/pii/S0968090X15004179", "title": "An automated sign retroreflectivity condition evaluation methodology using mobile LIDAR and computer vision - ScienceDirect" } ], "verdict": "corrected", "note": "Source corrected: the page first cited was read and is about something else; the sources listed state this.", "quote": false, "usedInEpisode": true }, { "n": 23, "claim": "Carlson and Picha (2009), quoted in that paper, found that 'the nighttime fatal crash rate is approximately three times that of the daytime crash rate, measured in million miles traveled.'", "sources": [ { "url": "https://www.sciencedirect.com/science/article/pii/S0968090X15004179", "title": "An automated sign retroreflectivity condition evaluation methodology using mobile LIDAR and computer vision - ScienceDirect" } ], "verdict": "corrected", "note": "Source corrected: the page first cited was read and is about something else; the sources listed state this.", "quote": false, "usedInEpisode": true }, { "n": 24, "claim": "An FHWA report from 2014 (FHWA-SA-14-017) noted that agency personnel were concerned about tort exposure from required minimum retroreflectivity levels.", "sources": [ { "url": "http://ntlsearch.bts.gov/ntl/md.do?id=74516", "title": "NTL Record" }, { "url": "https://rosap.ntl.bts.gov/view/dot/49516", "title": "DOT ROSA P" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 25, "claim": "An Iowa study using five years of Iowa DOT retroreflectivity data notes that earlier research tried to correlate retroreflectivity with crashes 'but a significant statistical relationship has not yet been found.' It found significant effects only for interstates, white edge lines, yellow edge lines and yellow centre lines.", "sources": [ { "url": "https://cornerstone.lib.mnsu.edu/me-cive-fac-pubs/29", "title": "Pavement Markings and Safety" }, { "url": "https://rosap.ntl.bts.gov/view/dot/18562", "title": "DOT ROSA P" }, { "url": "https://www.semanticscholar.org/paper/1e1927e099da407b8a78cc54ac13a46cefb4b89f", "title": "Pavement Markings and Safety | Semantic Scholar" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 26, "claim": "Bridget Burdett's 2010 University of Canterbury thesis found that adding a centreline raised mean speeds from 71.9 to 84.0 km/h, and adding an edgeline to a centreline-only road raised them from 86.0 to 97.3 km/h, on 100 km/h rural roads.", "sources": [ { "url": "http://hdl.handle.net/10092/5291", "title": "Speed Management on Rural Roads: The Effect of Pavement Markings" }, { "url": "https://ir.canterbury.ac.nz/items/1b291b07-c73f-4724-ba78-f98d409720b9/full", "title": "Speed Management on Rural Roads: The Effect of Pavement Markings" }, { "url": "https://ir.canterbury.ac.nz/items/1b291b07-c73f-4724-ba78-f98d409720b9", "title": "Speed Management on Rural Roads: The Effect of Pavement Markings" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 27, "claim": "Burdett concluded that 'an increase in delineation generally leads to an increase in speed.'", "sources": [ { "url": "http://hdl.handle.net/10092/5291", "title": "Speed Management on Rural Roads: The Effect of Pavement Markings" }, { "url": "https://ir.canterbury.ac.nz/items/1b291b07-c73f-4724-ba78-f98d409720b9", "title": "Speed Management on Rural Roads: The Effect of Pavement Markings" }, { "url": "https://ir.canterbury.ac.nz/items/1b291b07-c73f-4724-ba78-f98d409720b9/full", "title": "Speed Management on Rural Roads: The Effect of Pavement Markings" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 28, "claim": "SAE paper 2019-01-1014 by Adam Pike and Timothy Barrette (TTI) and Susannah Clear, Thomas Hedblom and Jordan Whitney (3M) tested a Mobileye lane-departure-warning system in continuous night-time rain from a rain tunnel, with and without headlight glare. It found that detection correlated with an interaction between the markings' diffuse luminance and continuous wet retroreflectivity.", "sources": [ { "url": "https://saemobilus.sae.org/papers/effects-wet-retroreflectivity-luminance-pavement-markings-lane-departure-warning-nighttime-continuous-rain-without-glare-sources-2019-01-1014", "title": "2019-01-1014: Effects of the Wet Retroreflectivity and Luminance of Pavement Markings on Lane Departure Warning in Nighttime Continuous Rain with and without Glare Sources" }, { "url": "https://trid.trb.org/view/1598911", "title": "Effects of the Wet Retroreflectivity and Luminance of Pavement Markings on Lane Departure Warning in Nighttime Continuous Rain with and without Glare Sources" }, { "url": "https://www.tib.eu/de/suchen/id/sae:21d5a5ef96a1187e70c4a2a8f582702834cc234a", "title": "Effects of the Wet Retroreflectivity and Luminance of Pavement Markings on Lane Departure Warning in Nighttime Continuous Rain with and without Glare SourcesIcon MastodonIcon InstagramIcon LinkedinIco" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 29, "claim": "The 2022 final rule's preamble says the sign and pavement-marking retroreflectivity rules are both based on the needs of older drivers with an average age of 62.", "sources": [ { "url": "https://www.govinfo.gov/content/pkg/FR-2022-08-05/html/2022-16781.htm", "title": "Federal Register, Volume 87 Issue 150 (Friday, August 5, 2022)" }, { "url": "https://www.lexfed.com/federal-register/2022-16781", "title": "National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for Streets and Highways; Maintaining Pavement Marking Retroreflectivity" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 30, "claim": "The preamble says that while the minimum levels are based on driver needs, the better markings will also improve the infrastructure's ability to work with advanced driver assistance systems (ADAS) and automated driving systems (ADS).", "sources": [ { "url": "https://www.govinfo.gov/content/pkg/FR-2022-08-05/html/2022-16781.htm", "title": "Federal Register, Volume 87 Issue 150 (Friday, August 5, 2022)" }, { "url": "https://www.lexfed.com/federal-register/2022-16781", "title": "National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for Streets and Highways; Maintaining Pavement Marking Retroreflectivity" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 31, "claim": "Section 406 of Public Law 102-388 (6 Oct 1992) told the Secretary of Transportation to revise the MUTCD to include \"a standard for a minimum level of retroreflectivity that must be maintained for pavement markings and signs, which shall apply to all roads open to public travel.\"", "sources": [ { "url": "https://www.lexfed.com/federal-register/2022-16781", "title": "National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for Streets and Highways; Maintaining Pavement Marking Retroreflectivity" } ], "verdict": "verified", "note": "Kept on a lower-weight source (lexfed.com); nothing we found says otherwise.", "quote": false, "usedInEpisode": true }, { "n": 32, "claim": "FHWA's 2015 evaluation by Craig Lyon, Bhagwant Persaud and Kimberly Eccles used an Empirical Bayes before, after design on roads upgraded to wet-reflective markings in Minnesota, North Carolina and Wisconsin. It found no earlier published research on how these markings affect crashes after they are applied.", "sources": [ { "url": "https://www.fhwa.dot.gov/publications/research/safety/15065/001.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 33, "claim": "Combined across the three states, freeways showed statistically significant reductions only in injury crashes (CMF 0.881) and wet-road crashes (CMF 0.861).", "sources": [ { "url": "https://www.fhwa.dot.gov/publications/research/safety/15065/009.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" }, { "url": "https://www.fhwa.dot.gov/publications/research/safety/15065/007.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" }, { "url": "https://www.fhwa.dot.gov/publications/research/safety/15083/index.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 34, "claim": "Wisconsin multilane roads showed significant reductions in total (CMF 0.825), injury (0.595), run-off-road (0.538), wet-road (0.751) and nighttime (0.696) crashes.", "sources": [ { "url": "https://www.fhwa.dot.gov/publications/research/safety/15065/009.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" }, { "url": "https://rosap.ntl.bts.gov/view/dot/29748", "title": "DOT ROSA P" }, { "url": "https://rosap.ntl.bts.gov/view/dot/35747", "title": "DOT ROSA P" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 35, "claim": "The report recommends no CMF for nighttime wet-road crashes. On two-lane roads, the crash sample was too small to show a statistically significant effect for any crash type.", "sources": [ { "url": "https://www.fhwa.dot.gov/publications/research/safety/15083/index.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 36, "claim": "Nighttime wet-road CMFs were 0.907 on North Carolina freeways, 1.170 on Wisconsin freeways and 1.001 on Wisconsin multilane roads, and none was statistically significant. North Carolina freeways also showed a statistically significant rise in dry-road crashes (CMF 1.087).", "sources": [ { "url": "https://www.fhwa.dot.gov/publications/research/safety/15065/007.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 37, "claim": "Benefit/cost ratios were 1.45 for freeways and 5.44 for multilane roads. Under USDOT sensitivity analysis they could range from 0.83 to 2.04 for freeways.", "sources": [ { "url": "https://www.fhwa.dot.gov/publications/research/safety/15065/009.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" }, { "url": "https://www.fhwa.dot.gov/publications/research/safety/15083/index.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" }, { "url": "https://www.fhwa.dot.gov/publications/research/safety/15065/008.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markings" } ], "verdict": "verified", "quote": false, "usedInEpisode": true }, { "n": 38, "claim": "A 2019 erratum removed the report's claim that two-lane roads showed signs of a safety benefit 'overall', keeping only the indication for wet-road crashes.", "sources": [ { "url": "https://www.fhwa.dot.gov/publications/research/safety/15065/index.cfm", "title": "Safety Evaluation of Wet-Reflective Pavement Markers Markings* , September 2015" } ], "verdict": "verified", "quote": false, "usedInEpisode": true } ], "removed": [ { "claim": "FHWA's Cathy Satterfield, presenting the proposed 50 and 100 mcd/m2/lx levels in a March 2018 TRB webinar, added the slide note: \"These numbers apply to dry markings per Federal Register notice.\"", "reason": "We could not find these exact words on any source we read." }, { "claim": "In its December 2007 final rule for signs, FHWA said it was still researching a pavement-marking minimum and would start that rulemaking once the research was finished and analysed.", "reason": "We could not find a public record about this either way." } ], "audioCheck": { "lines": 174, "matched": 174 }, "corrections": [], "verify": { "method": "1.3", "llmMode": "testing", "models": { "summary": "claude-haiku-5-5", "extract": "claude-haiku-5-5", "consolidate": "claude-haiku-5-5", "query": "claude-haiku-5-5", "read": "claude-haiku-5-5", "read_second": "claude-sonnet-5-5", "compare": "claude-haiku-5-5", "classify": "claude-haiku-5-5", "explain": "claude-haiku-5-5", "undash": "claude-haiku-5-5", "correct": "claude-haiku-5-5" }, "preScript": { "jobId": "job_C12ETYSWBN3JHSSTMYFK", "checkedAt": "2026-10-19T05:29:44.539Z", "counts": { "verified": 31, "corrected": 7, "removed": 2 } }, "episode": { "jobId": "job_QBK41D7VA3BEYH8VDH5D", "checkRef": "chk_CS0YMYKQVP6TVRHVJWQF", "trustPageUrl": null, "checkedAt": "2026-10-19T09:49:59.600Z", "score": null, "outcome": "not_rated", "counts": { "verified": 46, "not_verified": 4, "questionable": 23, "unable_to_determine": 11 }, "stability": { "spread": 15, "unstableClaims": 8, "pass": false }, "notVerified": [ { "k": 13, "claim": "The deadline for road agencies to comply with the federal lane line minimum was September 6, 2026, and it passed about six weeks before this episode.", "reasonText": "highways.dot.gov states something different: \"Final Rule Federal Register Notice Published on August 5, 2022 and effective September 6, 2022\"." }, { "k": 38, "claim": "Signs got their federal minimum in the 2009 edition of the manual, seventeen years after the 1992 law.", "reasonText": "FHWA states something different: \"New Retroreflectivity standards were added to the MUTCD in December 2007 and related compliance dates were revised in May 2012.\"." }, { "k": 41, "claim": "The manual requires longitudinal markings on roads with speed limits of 30 mph or greater to maintain retroreflectivity at or above 50 millicandelas per square meter per lux under dry conditions.", "reasonText": "mutcd-dr.fhwa.dot.gov states something different: \"a method designed to maintain retroreflectivity at or above 50 mcd/m2/lx under dry conditions shall be used for longitudinal markings on roadways with speed limits of 35 mph or greater.\"." }, { "k": 60, "claim": "Night and wet crash reductions were not statistically significant on any of the roads in the federal evaluation.", "reasonText": "fhwa.dot.gov states something different: \"For multilane roads, statistically significant reductions were estimated for total crashes (CMF = 0.825), injury crashes (CMF = 0.595), run-off-road crashes (CMF = 0.538), wet-road crashes (CMF = 0.751), and...\"." } ], "questionable": [ { "k": 9, "claim": "When water covers a glass bead in a road line, the light it returns is aimed away from the driver, because water bends light differently from air.", "reasonText": "Only one source states this: saemobilus.sae.org." }, { "k": 20, "claim": "Fixes for wet-night line visibility were tested on a Texas test course in 2009.", "reasonText": "Sources only partly back this: FHWA." }, { "k": 24, "claim": "In the 2009 Texas test, the prototypes in wet reflective tape kept 60 to 80 percent of their dry detection distance.", "reasonText": "fhwa.dot.gov gives context that changes the meaning. Our summary: The 60 to 80 percent figure applies to the wet-recovery condition; in continuous rain the figure was 50 to 70 percent." }, { "k": 25, "claim": "The federal highway administration's research synthesis says road lines are usually brighter when dry than when wet.", "reasonText": "Sources only partly back this: rosap.ntl.bts.gov." }, { "k": 26, "claim": "The federal highway administration says a line's wet performance cannot be predicted from how it measures dry.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 31, "claim": "The old lab wetting test rained eight to 20 times harder than most Texas storms ever got.", "reasonText": "Sources only partly back this: DOI resolver." }, { "k": 35, "claim": "A federal summary says the work on retroreflectivity standards sped up in 1984.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 40, "claim": "The lane line got its federal brightness number about thirty years after the 1992 law first asked for one.", "reasonText": "Only one source states this: lexfed.com." }, { "k": 50, "claim": "The 2012 Virginia study set its own minimum wet level at 150.", "reasonText": "Reliable sources disagree about this." }, { "k": 55, "claim": "The federal highway administration ran its own evaluation of wet reflective lines in 2015.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 56, "claim": "Roads in Minnesota, North Carolina and Wisconsin were upgraded to wet reflective lines in the federal evaluation.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 57, "claim": "The federal evaluation's authors could not find earlier published work on how wet reflective lines affect crashes.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 59, "claim": "On Wisconsin's multilane roads, the federal evaluation found that several crash types fell after the upgrade.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 61, "claim": "The federal evaluation report does not recommend a number for night and wet line brightness.", "reasonText": "Sources only partly back this: FHWA." }, { "k": 62, "claim": "North Carolina freeways showed a statistically significant rise in dry road crashes after the wet reflective line upgrade.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 63, "claim": "On two-lane roads, the federal evaluation did not have enough crashes to show any effect.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 68, "claim": "A 2007 Texas study says wet night lines are not a replacement for raised reflective markers.", "reasonText": "The fact holds, but the named source does not say it." }, { "k": 69, "claim": "Bridget Burdot of the University of Canterbury, New Zealand, published a 2010 study of speeds on rural roads.", "reasonText": "Only lower-weight sources state this: hdl.handle.net and 1 more." }, { "k": 70, "claim": "The New Zealand study examined rural roads with a 100 kilometer per hour speed limit.", "reasonText": "Only one source states this: hdl.handle.net." }, { "k": 73, "claim": "Burdot concluded that more delineation generally means more speed.", "reasonText": "Only one source states this: hdl.handle.net." }, { "k": 76, "claim": "In 2019, two Texas Transportation Institute researchers and three 3M researchers tested a Mobileye lane departure warning system in a rain tunnel.", "reasonText": "Only one source states this: saemobilus.sae.org." }, { "k": 78, "claim": "In the 2019 rain tunnel test, whether the camera found the line depended on how much light the wet line returned and how bright the paint looked under ordinary scattered light.", "reasonText": "Only one source states this: saemobilus.sae.org." }, { "k": 81, "claim": "A 2014 federal report noted that agency staff worried a required minimum would expose them to lawsuits.", "reasonText": "The fact holds, but the named source does not say it." } ] } } }