In 1990, the year Carey Pinkowski became the Chicago Marathon's executive race director, six of the field's 6,168 finishers crossed the line after six hours, about one-tenth of one percent. By 2023, roughly 7 percent of the race's 48,000 finishers took six hours or more, and the same results held in 2025. 4,298 of 54,328 official finishers, or 7.91 percent, crossed at six hours or later, according to Chicago's own results database. The slowest official finisher that year crossed in 10 hours, 2 minutes, 21 seconds. A question that barely applied to anyone in 1990 now applies to thousands of finishers in that one race alone: what happens when a marathon's clock runs out before a runner runs out of course?
A marathon's cut-off time is the deadline organizers set for finishing before a runner loses some combination of three things: the right to keep running the certified route, on-course support like water and medical stations, and an official recorded time. Which of those three applies, and when, is not standardized. Among the World Marathon Majors and the Marine Corps Marathon, published overall limits run from an effective six hours at Boston to eight hours at London, and the pattern holds across ordinary marathons too.
What a cut-off time is, and why the number moves
Boston's rulebook sets official timing to stop at 5:30 p.m., which works out to about six hours after the last starter crosses the line; anyone still out there afterward becomes what the B.A.A. calls a "post-race participant," excluded from the official results. London's 2026 Participant Event Guide gives entrants eight hours from the last starter at 11:30 a.m., with The Mall closing at 19:30; the 2027 edition keeps the same eight-hour pace but moves the late finish to a secondary line in Green Park that stays open until 23:59:59. Berlin sets 6 hours 15 minutes from a runner's own start-line crossing, backed by an absolute 5:00 p.m. course close. Chicago publishes 6 hours 30 minutes, tracked by an event vehicle holding a 15-minute-per-mile pace behind the last starter. Tokyo's limit is seven hours measured from the starting gun rather than from an individual's own crossing, which matters: a runner starting several minutes behind the gun has correspondingly less real time. The Marine Corps Marathon states a 14-minute-per-mile required pace but enforces it through three absolute-clock checkpoints instead.
New York is the case most often misreported. New York Road Runners runs a blanket time-cutoff policy across its races, built on a 20-minute-per-mile pace, but NYRR's own policy page names the TCS New York City Marathon as one of the events that policy does not cover. The marathon runs its own rule instead: a 16-minute-per-mile pace measured from the fifth and final starting wave at 11:30 a.m., with official finishers recorded through 10:00 p.m. A runner in that last wave gets 10 hours and 30 minutes of clock before that deadline, more room than any other Major offers, and a runner in the first wave, starting at 9:10 a.m., gets 12 hours and 50 minutes.
The same spread shows up well beyond the Majors. Of the 447 marathon-distance races in 42cal's race database, 75 record a cut-off or course-closure rule, and 51 of those publish a single overall figure. Among those 51, 6:00 is by far the most common, chosen by 15 of them. Two races, Tunisia's COMAR Tunis-Carthage and Serbia's Novi Sad, set the tightest published limit at 5:00. China's Great Wall Marathon sets the loosest at 8:00. Overall, 23 of the 51 races, 45 percent, cap the course at six hours or under, and only two of the 51 allow more than seven.
The checkpoint cut-offs partway through the course
A single finish-line deadline is the easiest part of a marathon's cut-off to fail, and it is not the only one. Tokyo, Berlin, the Marine Corps Marathon, and a number of smaller races in 42cal's database also enforce checkpoints partway through the course, and those checkpoints do not always track the overall pace a runner thinks they are running to.
Tokyo's cut-off table for its 2027 edition, which the race itself labels provisional, names nine gates, and their pace requirements do not move in a straight line. The first, at kilometer 4.9, closes at 10:25 a.m., allowing a pace slower than 15 minutes per kilometer, far looser than the race's 9:57-per-kilometer overall limit. By kilometer 33.5, the Sukiyabashi intersection, the deadline tightens to 9:42 per kilometer, already stricter than the finish limit. At kilometer 38.5, Shiba Park, it tightens again to 9:37 per kilometer. A runner holding exactly the pace that would make Tokyo's seven-hour limit at the finish line is, by that gate, already too slow to clear it.
Berlin's gates run the opposite direction. Its two checkpoints, at kilometer 33 and kilometer 38, both allow a pace looser than the race's 6:15 net finish limit; they function as backstops that catch only runners who are already badly behind. (Berlin's own site is inconsistent about the exact times: its FAQ lists kilometer 33 at 3:50 p.m. and adds a kilometer 38 gate at 4:35 p.m., while its separate race-day page lists kilometer 33 at 3:40 p.m. and mentions no second gate. Both pages were live on the same day this was checked, a small but real illustration of how a runner trying to plan around an official number can still get conflicting official numbers.)
The Marine Corps Marathon works differently again. Its three named gauntlets, the DC Gauntlet, Beat the Bridge, and the Crystal City Gauntlet, divert runners off the certified course rather than pulling them from it; a runner who misses one may keep running but has not completed 26.2 miles and will not be recognized as an official finisher. The math behind the gates is looser than the marathon's own headline pace: the race states 14 minutes per mile as the required pace, but Beat the Bridge, at Mile 20 by 1:15 p.m. from a 7:20 a.m. gun, allows 17 minutes 45 seconds per mile, considerably more forgiving than advertised. The stated pace functions as guidance; the gauntlet clocks are what remove people.
The pattern extends well past the Majors. In 42cal's database, Italy's Maratona di Pisa closes an intermediate checkpoint at kilometer 30, 4 hours 35 minutes into a race with a 6:30 overall limit. Jordan's Petra Desert Marathon closes a checkpoint at kilometer 31 five hours after its 6:30 a.m. start, inside a 7:00 overall window. Neither gate is loose padding; both are designed to catch a runner before the finish-line number ever comes into play.
Why the closures work this way
Boston, Chicago, and New York all enforce their overall limits with a rolling closure, and it behaves less like a clock than like a moving line. A vehicle travels the course holding the limit pace directly behind the last starter, and everything behind that vehicle, timing mats, water stations, marshals, road closures, stops existing as it passes. Boston states this most plainly: once the roads begin reopening, "timing systems, course clocks, medical stations, and water stations" all begin to close, and the race's own course page describes a team of cyclists trailing the field at roughly 13:44 per mile to help anyone still out there.
The vehicle itself has a name with an odd history. The French term is voiture balai, or broom car, and the concept originated at the 1910 Tour de France, introduced by organizer Henri Desgrange the year the route first climbed into the high Pyrenees. A rider who fell in behind the wagon left the official convoy and had to follow ordinary road traffic law from that point on, the same split a marathon draws between a runner still on the closed course and one who has been asked to move to the sidewalk. Each Major has its own name for the modern version: Berlin's is the broom bus, New York's is the sweep bus, London's are sweep vehicles and minibuses, and Chicago's are Runner Transport vehicles. Four names, one object, one job.
What happens to a runner who is caught
The first thing a caught runner loses is usually the official time. The medal often survives. Boston's caught runners still receive a finisher's medal; New York's do too, explicitly, even after the 10:00 p.m. deadline. Neither appears in the official results. Berlin is stricter on both counts: a runner pulled from the course there receives no result and no medal, and the event FAQ states plainly that continuing at one's own risk is not permitted.
The sharpest distinction, though, is between being swept and being slow. New York states it directly: a runner who boards a sweep bus cannot cross the finish line and is not recorded as an official finisher, full stop, while a runner who instead moves to the sidewalk can still finish and still be counted, right up until 10:00 p.m. The bus ends the attempt. The sidewalk does not.
Where the data disagrees. The common assumption is that crossing a marathon's published cut-off erases a runner from the results outright. Chicago's own 2025 results contradict that directly. The race publishes a 6-hour, 30-minute course limit and states that finishers after 4:00 p.m. "may not be recorded or published as official finishers," yet the results list runs to 54,328 names, the last one 3 hours and 32 minutes past that published deadline. The gap is not a data error. Chicago's stated limit describes when on-course support and traffic control end, not when the results system stops accepting a time, and the two are enforced separately.
Missing a cut-off and Boston qualifying status
A course time limit is a separate mechanism from the registration cutoff covered in Why Boston Marathon Qualifying Cut-Offs Are Hard to Predict, the margin below a qualifying standard needed to get a bib once results close. The course time limit governs whether a finish counts at all; the registration cutoff governs whether an already-qualifying time was fast enough to get in.
USATF and RRTC certification rules concern only measured distance, calibration, and tolerance between measurements; neither document mentions time limits at all. Certification governs measurement, and says nothing about how long a course stays open. Boston's own qualifying rules require a certified course and a verifiable official result, which is the point of contact between the two questions: a runner caught by Boston's 5:30 p.m. clock becomes a post-race participant with no official finisher result, and without an official result there is nothing to submit as a qualifying time. The course is not the problem. The runner has no time on record to use. A runner unsure whether a projected finish clears a given race's standard can check it against 42cal's Boston qualifier calculator before entry.
Whether walking is allowed at all
Most big-city marathons enforce a pace requirement rather than a gait, and say nothing explicit about walking either way. Two races sit at the poles. Honolulu has no cut-off at all: its own FAQ states there is "no cut-off time" and that walkers are welcome, though officials retain the right to remove anyone for safety. Johannesburg City Marathon, at the other end, welcomes walkers on its half marathon and 10K but bars them from the full, alongside a 26-kilometer intermediate cut-off at 9:30 a.m. London sits in between and leans permissive: its guide tells entrants to move to the left if they need to walk, and predicted finishers over seven hours are deliberately assigned to a separate start, the Pink Start. Some races split the difference with logistics rather than a ban: the Bellingham Bay Marathon starts walkers 45 minutes ahead of runners, so both groups share the same 2:00 p.m. course closure while walkers get 7 hours 15 minutes of course time against the runners' 6:30.
Finding a start line with room to spare
None of this changes the arithmetic that opened this piece: in Chicago's 2025 field only about one finisher in thirteen went past six hours, and about one in 78 past seven, so the overwhelming majority of finishers land well inside even a strict published limit. A runner choosing between a tight-limit race and a generous one has real options, though comparing them means reading the reference point as carefully as the number.
Grand Rapids Marathon publishes no hard finish cutoff at all, with on-course support tapering off around 2:00 p.m. Honolulu and London both build room in deliberately. 42cal's race predictor can turn a recent training pace into a realistic finish-time estimate before entry, its pace calculator converts any published limit into the per-mile or per-kilometer pace it demands, and the site's country browser makes it possible to compare a race's published limit against dozens of others before committing to one that leaves no margin at all. First-timers weighing that decision may also find the most common mistakes reported by 50,000 debut marathoners useful.
