IH-35 has been under construction since 1960 and will be under construction in the year 2060. I frequently travel it and avoid it whenever possible. U.S. Highway 281 is a very good alternative as are several other routes. If you must travel 35 the best time to do so is late at night or early morning because after about noon it's a mess and traffic can and will grind to a halt for the first fender bender. This often results in a backup for both directions as the gawkers have to slow to a crawl in order to view the carnage.