Pretty sure a 2 1/2 year old can ride, but as to whether they will want to...not sure. My DS5 went on it but was very skeptical at first. After he rode it hough, he wanted to go again!
We took my DD last year. She was 2 1/2 at the time and loved it. The CM made her sit next to me rather than on my lap. I just wrapped my arm around her and held on tight.