TRAFFIC ALERT: Southbound traffic shift Wednesday on Houghton Road Drivers are asked to travel through the area with caution and to remember speed limits on these construction zones will be limited 25 miles per hour. (Source: TxDot) By KOLD News 13 Staff | April 13, 2021 at 4:36 PM MST - Updated April 14 at 5:35 AM TUCSON, Ariz. (KOLD News 13) - Southbound traffic on Houghton Road from Valencia Road to Mary Ann Cleveland Way will switch to the west side of the roadway onto new asphalt on Wednesday, April 14. The Tucson Department of Transportation says northbound traffic is scheduled to switch onto the west side of the roadway on Monday, April 19.