75mm recoilless with autofeed on a servo mount is the best approach to traffic.150mm if trucks are more common.
(
Tahkcalb ω∞ for sigs,
Tue 31 Mar 2009, 7:19,
archived)
I'd settle for a high-explosive armour-piercing donk
Bela Lugosi's Dad,
Tue 31 Mar 2009, 7:23,
archived)