This is a rational question and a legitimate concern. Fortunately, there are also good answers for a long span crossing of multilevel highway (expressway) interchanges, where any ground based maintenance (with cranes, ladders or cherry-pickers) would be not only undesirable but also virtually impossible. There are two approaches, as follows:

For routine maintenance, the special gasoline or diesel powered emergency maintenance vehicle (EMV) can access any portion of cable-suspended rails or the power distribution catenaries, even in case of power failure, for repairs, inspection, or any other maintenance function (as well as to tow any disabled vehicles).

As far as the pylons and suspension cables are concerned, they are routinely inspected and maintained both in the Alpine and domestic installations, hundreds and thousands of feet above ground. There are an increasing number of domestic suppliers and representatives of European experts with highly experienced specially trained crews, and a variety of special equipment, to provide maintenance and inspection and cable replacement in the field at almost any difficult locations as the following pictures illustrate.