The Tour of downtown Houston and trip to the NASA Space Facility: The 2 drivers were friendly and informative. The information about Houston was a combination of the driver on a micropone and pre-recorded tapes. Not always the easiest to understand along with accents of the speakers. Information was given in both English and Spanish and I think that was appropriate for the audience. The NASA Space Facility was not the responsibility of the company doing the transportation so I will not include it here. The negative part of the experience and reason for the 2 rating was the condition of the transportation vehicles. The double decker bus for the first part was in poor condition. If you were sitting up top you had to dodge branches and acorns. If you chose to sit on the lower level the windows were filthy and the smell of exhaust filled the cabin. Then we transfer to a bus for the trip to NASA that has the lettering for a Baptist Church on it! Where did this bus come from is the question. It was in better condition but the seatbelts were hard to find and use. The overall impression is that Viator contracts with a local company but probably has no idea of the conditions of the vehicles. You start to wonder if this would be the same situation in any city you would visit that Viator offers tours and if so would you want to find another company other than Viator.
Strongly recommended!! NASA is amazing and the city tour is interesting.