Human High Tide
"Human high tide" is another term for "rush hour." The difference is that the former term ("human high tide") concerns people and the latter term ("rush hour") usually concerns vehicles.
http://www.nytimes.com/2006/03/26/nyregion/26commute.html?_r=1&oref=login
Expanding Workday Makes Its Mark on Transit
By PATRICK McGEEHAN
Published: March 26, 2006
(...)
The peaks of the commuter traffic known to some transit officials as "human high tides" still occur just before 9 a.m. and just after 5 p.m., but more and more commuters are straying from the herd. And the shift extends beyond New York. On Chicago's Metra train service, the fastest growth in ridership last year came on trains arriving between 6:30 and 7 a.m. at Union Station in downtown and those departing between 6 and 6:45 p.m., said Tom Miller, a Metra spokesman.
http://www.nytimes.com/2006/03/26/nyregion/26commute.html?_r=1&oref=login
Expanding Workday Makes Its Mark on Transit
By PATRICK McGEEHAN
Published: March 26, 2006
(...)
The peaks of the commuter traffic known to some transit officials as "human high tides" still occur just before 9 a.m. and just after 5 p.m., but more and more commuters are straying from the herd. And the shift extends beyond New York. On Chicago's Metra train service, the fastest growth in ridership last year came on trains arriving between 6:30 and 7 a.m. at Union Station in downtown and those departing between 6 and 6:45 p.m., said Tom Miller, a Metra spokesman.