Total Time on Duty [Transportation] Law and Legal Definition

According to 49 CFR 228.5 [Title 49 – Transportation; Subtitle B -- Other Regulations Relating to Transportation; Chapter II -- Federal Railroad Administration, Department of Transportation; Part 228 -- Hours of Service of Railroad Employees; Subpart A – General], total time on duty (TTOD) means “the total accumulation of time spent in periods of covered service and commingled service between qualifying statutory off-duty periods of 8 or 10 hours or more. Mandatory activities that do not constitute covered service, such as rules classes, when they may not attach to covered service, are counted as limbo time, rather than commingled service, which limbo time is not counted toward the calculation of total time on duty.”