Maybe this will help you: r-e-v-e-n-u-e.
That explanation would suffice — except that, reportedly, nobody was ticketed. It would have been a lucrative deal for tow truck operators paid by the city by the hour. But I think the city just liked the idea of pushing the little people (’s cars) around. Doubtless the official explanation was to obviate the possibility of any car bombs being near the presidential procession.