PSAs and enforcement. Tell people what you're going to start enforcing, then aggressively enforce it for a few months, then continue moderately enforcing and focusing on hot spots.

For example, turning into the correct (nearest) lane is a major issue. Tell people what they're supposed to do via TV, radio, newspapers, online news, twitter, Facebook, Reddit, etc. Then a month later camp out at the worst intersections everyday. Initially be generous with warnings. Then start giving out tickets. Reduce enforcement eventually, but the baseline needs to be better than it is now.

Then listen to people complaining about how their taxes should be spent on property crime and not traffic enforcement and ask yourself what's even the point?