With the ABS and ATC lights on the Antilock Brake System and the Automatic Traction Control systems are both inoperative. There is no harm in driving the coach in this condition unless you experience a low traction situation and need one of these systems. The need for one or both of these systems is much higher if you drive on snow covered or icy roads, although wet roads can give poor enough traction to make them very valuable also.
If you decide to have the problem repaired, the repair shop of choice will vary with your location. A system malfunction is usually caused by a defective wheel speed sensor, and can be diagnosed by any shop with competent technicians and a computer scanner that will read the system fault codes and data.
The most common repair shop recommended on this forum will be Beaver Coach Sales of Oregon or Alliance Coach in Florida. Either one of these shops would be an excellent choice, unless you are in some place like Texas or Kansas and it would obviously not be worth the drive.
Gerald
