This year, Houston's largest and most Housterrific annual event runs down Smith Street Saturday 14 April. More than 100,000 Art Car fans will likely turn out for the parade.
This is an above-average event for signature-gathering. Get there early to catch people finding there vantage points, or in line at the food trucks, rather than distracting them from the parade. There should be chances to find signers after the parade as well.
1600 Smith St
Houston, TX 77002
Google map and directions