during the 12-month period immediately following his arrival in the general location of his new principal place of work, the taxpayer is a full-time employee, in such general location, during at least 39 weeks, or

during the 24-month period immediately following his arrival in the general location of his new principal place of work, the taxpayer is a full-time employee or performs services as a self-employed individual on a full-time basis, in such general location, during at least 78 weeks, of which not less than 39 weeks are during the 12-month period referred to in subparagraph (A).

For purposes of paragraph (1), the distance between two points shall be the shortest of the more commonly traveled routes between such two points.