The Shulchan Aruch (או”ח צ טז) says that in order to Daven with a Minyan one is obligated to travel four Mil if he will be continuing on his way or 1 Mil or 18 minutes if he will be going backwards. One who is in his house is also reqiured to travel one Mil or 18 minutes.

What if one has a car or other means of transportation at his disposal, does he need to travel a Mil which would take him far less than 18 minutes or is he obligated to travel 18 minutes?

The Bais Yaacov says that this is comparable to our Gemora, where one in Modiin is defined as far away, although he may have a horse at his disposal. So too, we would consider someone with a car as far away, although he could get here quite quickly with his car.

However, the Yeshuos Yaacov refutes his proof, proposing that Pesach is a Geziras HaKasuv, and is an exception, not the rule.