According to a reader the driver of the truck below was seen harrassing cyclists on Broadway, honking, yelling slowing down and driving next to them. It all started near the intersection of Alpine and Broadway and as he traveled north harassed any cyclists in his path until the stopped in North Boulder for gas. Picture of the truck can be seen below (Texas plates). The reader also snapped a photo of the driver (not sure if we can post that) but he looks to be a male in his 40's
Sorry, had to blur the plates but if the authorities would like the original we have it.