Section 4 of the Portal Act, which relates to so-called ``portal-to-
portal'' activities engaged in by employees on or after May 14, 1947,
provides as follows:
(a) Except as provided in subsection (b), no employer shall be
subject to any liability or punishment under the Fair Labor Standards
Act of 1938, as amended, * * * on account of the failure of such
employer to pay an employee minimum wages, or to pay an employee
overtime compensation, for or on account of any of the following
activities of such employee engaged in on or after the date of the
enactment of this Act:
(1) Walking, riding, or traveling to and from the actual place of
performance of the principal activity or activities which such employee
is employed to perform, and
(2) Activities which are preliminary to or postliminary to said
principal activity or activities
which occur either prior to the time on any particular workday at which
such employee commences, or subsequent to the time on any particular
workday at which he ceases, such principal activity or activities.
(b) Notwithstanding the provisions of subsection (a) which relieve
an employer from liability and punishment with respect to an activity,
the employer shall not be so relieved if such activity is compensable by
either:
(1) An express provision of a written or nonwritten contract in
effect, at the time of such activity, between such employee, his agent,
or collective-bargaining representative and his employer; or
(2) A custom or practice in effect, at the time of such activity, at
the establishment or other place where such employee is employed,
covering such activity, not inconsistent with a written or nonwritten
contract, in effect at the time of such activity, between such employee,
his agent, or collective-bargaining representative and his employer.
(c) For the purpose of subsection (b), an activity shall be
considered as compensable under such contract provision or such custom
or practice only when it is engaged in during the portion of the day
with respect to which it is so made compensable.
(d) In the application of the minimum wage and overtime compensation
provisions of the Fair Labor Standards Act of 1938, as amended, * * * in
determining the time for which an employer employs an employee with
respect to walking, riding, traveling, or other preliminary or
postliminary activities described in subsection (a) of this section,
there shall be counted all that time, but only that time, during which
the employee engages in any such activity which is compensable within
the meaning of subsections (b) and (c) of this section.
