My parents will be arriving at JFK T3 on Comair, and leaving from T4 on Air India. I see the options listed on the JFK site, and ages ago I remember walking between adjacent terminals. They are in their 70s and generally get around well. What's the best way to connect? What isn't clear about the Airtrain is whether when connecting between terminals you have to take the inner track going the long way around. They have about four hours to connect.

They'll just have two hours to connect the other way on the return. Is there a way to expedite the transfer, such as arranging Autolink?