Card only but only had cash. Worker let me in then when I was ready to leave someone drove out right away to collect my coins. Great service for only$2 per day.
Really cheap parking ($1 per day), and easy to register for overnight parking (up to 3 nights at a time) by phone. Not much else to be said about it.
This parking lot is just for one dollar a day so it's much cheaper than the other lots in rice university..
Specially if you planning to stay a couples of hours