TxDOT has standard sheets and policies regarding temporary traffic control (TTC) necessary for a variety of work operations. The TTC necessary for each situation depends on the type of highway, road user conditions, duration of operation, physical constraints, and the nearness of the work space to road users. The needs and control of all road users through a TTC zone shall be an essential part of highway maintenance operations. One of the fundamental principles of TTC in the Texas MUTCD is that the goal should be to route road users through such zones using devices as nearly as possible comparable to those for normal highway situations.

An activity such as replacing a small ground-mounted sign in the field is typically a short-term stationary TTC zone operation as defined in the Texas MUTCD and a plan for conducting the operation, including traffic control, should be determined before the work begins. When a STOP or YIELD sign is being replaced and is temporarily removed from the view of motorists, provisions should be in place to ensure motorists are provided with necessary information by utilizing a temporary roll-up STOP or YIELD sign or a flagger until the permanent sign is in place.

Requirements regarding existing signs in TTC zones are contained in Note 3 on standard sheet BC(4) as follows:

"When existing permanent signs are moved and relocated due to construction purposes, they shall be visible to motorists at all times." Additionally, guidance on the standard sheet states "Permanent signs are used to give notice of traffic laws or regulations, call attention to conditions that are potentially hazardous to traffic operations, show route designations, destinations, directions, distances, services, points of interest, and other geographical, recreational, or cultural information. Drivers proceeding through a work zone need the same, if not better route guidance as normally installed on a roadway without construction.”