The ramps I have look like the ones below, which have braces on the sides.Ive got a set of those ramps. They are made of very thick gauge steel and heavy. Drive up them, put it in park and set the parking brake. I feel safer with these than with jack stands.
However, I also put jack stands under the car when using the ramps.
Of course, you have to remember to first remove the jack stands before trying to drive back off the ramps.