If you drive, or walk, through downtown Los Angeles , you’ll likely come across one of the area’s many construction projects. High-rise towers going up, like the Wilshire Grand and another subway stop at 2nd and Broadway are among them. Add a healthy dose of street closures for commercial and T-V shoots and you have a recipe for a ton of traffic. Southern California already holds the dubious record of having the worst traffic in the nation. So what's causing it and what are city leaders doing?