With RTD set to phase in paid parking at 39 selected park-n-Ride lots early next year, you may be surprised to know that it might not affect you at all. Here's an explanation:

* What parking lots are affected?

RTD's busiest lots are on the major commuting corridors. Paid parking will be in lots on I-25 north in Adams County, I-70 east from Stapleton to Pena Boulevard, the light-rail corridors from downtown to Lincoln Avenue and Nine Mile on I-225, and the Southwest Corridor to Littleton; U.S. 36 into Boulder; plus outlying lots in Lyons and Pine Junction.

* What is the charge?

Most people won't pay. Daily commuters who live in the RTD taxing district, which covers all or parts of eight counties, won't pay anything if they park, take the bus or train, then return and leave at the end of the day. But vehicles registered outside the RTD taxing district will be charged $4 a day in high-demand lots and $2 a day in low-demand lots. District residents will only pay if they leave their vehicles longer than one day, with a charge of $2 a day after the first day in a high-demand lot and $1 a day in a low-demand lot.

* How will RTD police the lots?

RTD has contracted with Central Parking to patrol these lots at least twice a day, every day.

* How do I pay?

Two ways. Central Parking will install solar-powered wireless payment kiosks similar to those at its many pay lots. Enter your license plate number and pay the amount indicated. You don't need to place a receipt on your dashboard because the information is instantly uploaded into Central Parking's computers.The second way is with a prepaid account, similar to electronic tolling. Sign-up will be by phone or online, and account holders will get a 15 percent discount on parking charges.

* How will RTD know whether a vehicle is owned by a resident or nonresident?

Central Parking's vehicles are equipped with cameras, digital scanners and computers loaded with a database of all license plates registered within the RTD boundaries, updated daily with new registrations.