The first Monday in January is when millions of people usually get back into their cars and hit the road to go to work or to school. Along the way, many pay a few euros at a toll plaza, adding their contribution to repay billion-euro investments made in road infrastructure through multi-decade public and private financing schemes. On January 4, however, the daily traffic report from the state agency Transport Infrastructure Ireland (TII) showed that car numbers were down 40 per cent on the same day last year on the M50 toll bridge, and up to 51 per cent on…