Mark the following dates on your calendar if you regularly use the Portland Aerial Tram or are making plans to ride it, perhaps with out-of-town visitors:

Friday, Aug. 31, through Monday, Sept. 3: The Tram will be out of service for routine annual maintenance. Service is scheduled to resume at 6 a.m. on Tuesday, Sept. 4. Doppelmayr CTEC, which operates the Tram under contract with Oregon Health & Science University, will shorten and splice the haul rope and also perform required annual tests of the haul rope and of carriage grip slippage. Shortening of the haul rope is normally required during the first year of service and is not likely to be necessary again for eight to 10 years.

Sunday, Sept. 16: This is the last Sunday of the year the Tram will be in service. Sunday service was inaugurated on May 20 to accommodate the expected increase in summer traffic, which in fact materialized. More than 18,000 fare-paying riders boarded the Tram in July compared with 12,950 in May. During the winter months, Tram service was not offered to permit maintenance work during daylight hours. The Tram Executive Management Committee will determine whether to resume Sunday service next spring after carefully evaluating the advantages and disadvantages of doing so.

Saturday, Aug. 18, from 9 a.m. to 5 p.m., and Sunday, Aug. 19, from 1 to 5 p.m. Free Tram rides will be offered during the grand opening celebration of the Portland Streetcar S.W. Lowell extension. The extended Streetcar service will be inaugurated at 11 a.m., Aug. 17. For more information about the grand opening, go to http://www.portlandstreetcar.org/.

The Tram opened to the public on Jan. 27, 2007. Since then more than 670,000 riders have been welcomed on the popular aerial conveyance. Given current numbers, the Tram is likely to greet its one-millionth rider in late September or early October.

For further information about the Tram, go to www.portlandtram.org.