Investor argues performance of uniform-rental companies is good gauge of U.S. hiring trends.

Companies increasingly use dedicated-fleet services amid shortage of drivers.

Companies increasingly use dedicated-fleet services amid shortage of drivers.

Temporary staffing companies payrolls grew 10.7% in June.

Temporary staffing companies payrolls grew 10.7% in June.

Rise in freight volumes points to gains in industrial production.

Rise in freight volumes points to gains in industrial production.

Change could signal salary increases for permanent employees.