Here’s a look at downtown traffic on Friday night. On the bike it doesn’t seem so bad. After I boarded the bus it took a while to get across town.
If you must drive, consider driving to one of the park and ride lots next to a light rail station, then take light rail to downtown. If you bike, you don’t need to ride with the heavy traffic on Santa Clara Street like I did for this video. San Fernando Street is much better for biking. Free secure bike parking is available on Paseo de San Antonio between the Fairmont and Muji just west of First Street.