The 24E bus starts up from 25th Street and Fairfax Drive in Arlington at 7:55 a.m. -- precisely. It stops at the Pentagon Metro station at 8:40 a.m. -- precisely. It is faithful to the Metrobus schedule.

The interior is graffiti-free, the ventilation good, the seats padded and comfortable, and the floors clean. The bus is filled but not crowded. The driver is friendly and patiently answers each question put to him.

Riders say that's the way it almost always is on the 24E, a 10.1-mile run through Arlington. And, in fact, their assessment of the 24E was borne out by a Washington Post survey that found it is one of the 10 best routes in the Metro system.

As a rush-hour commuter line, it is typical of the majority of the best routes. Metro officials attribute the 24E's reliability to good bus maintenance, a schedule that is less demanding than all-day operation and the fact that the roads it travels are in good shape.

One rider has an additional explanation: "The general manager of Metro uses this line. Sure it's reliable."

On this particular run there is no sign of Richard Page, who is a regular on the bus, but a woman questioned about her views on Metrobus laughingly confesses: "I'm Edith Page. You probably won't want to talk to me." Mrs. Page quickly adds: "I take the Metro every day, and I love it."

The 24E rider typically is a lawyer or businessman, commuting to and from work in downtown Washington, wearing a three-piece suit and carrying an attache case.

Lost in their reading, riders largely ignore the outside world as it flows by -- small brick homes, tree-lined streets, car washes, palm readers, funeral homes, used car dealers and numerous Vietnamese shops.

In the morning, the 24E starts from a western corner of Arlington, near Falls Church, and travels to the Ballston, Clarendon and Pentagon Metrorail stations. It operates eight times a morning, every 20 minutes, beginning at 5:55 a.m. The last run starts at 8:15 a.m. and arrives at the Pentagon Metro station 45 minutes later.

In the evening, the 24E operates in the opposite direction, with the first bus leaving the Pentagon station at 4:10 p.m. Five more buses make the run, at 20-minute intervals.

William Dillinger, an economist at the World Bank, is a daily commuter, catching the bus about a block from his home and getting off at the Ballston Metro stop, where he takes the subway into the city. The entire trip, from his house to his office, takes about 30 minutes, he said.

"This line is very good. The Metrorail is more unreliable," he says. "Even the weather seems to hurt Metrorail more than the buses." Dillinger says the 24E buses are always in good condition, and he compares the service favorably to San Francisco's: "Those buses were three deep in the aisles" and the equipment was "old and decrepit."

Dillinger says his only complaint is that the buses in the evening tend to run a minute or two early. Thus he will sometimes arrive at the Ballston Metro stop at the scheduled time, only to find that the bus has already left and that he has a 20-minute wait.

Linda Gaston, who lives in D.C. and works in Arlington, prefers the D.C. lines because they run more frequently, but the buses in Virginia "are in better condition. The transmissions on the buses in D.C. sound like they're going to go in a minute."

Paul Moore, a daily commuter from Williamsburg Boulevard in Arlington, says his 50-minute commute to his downtown office via the bus and the Metrorail never varies by more than 10 minutes. He has commuted about eight years and says the service "is better and more reliable now. The buses used to break down more often. You were not certain they would be there. Now there is no problem."

The driver of the 4:30 p.m. run, Hilda Sheeler, agrees that the 24E buses are in "very good condition." She adds, "I've never had one on this line to break down."

Bob Mills, driver of the 7:55 a.m. bus, says that the 24E is "a good run. The workload is easy." He notes that the route goes along back streets and not into heavy traffic, and that the schedule was planned so that there is enough time in between stops to answer riders' questions, which is not the case on some other lines.

Mills adds, "Working out here is one heck of a lot better than working in D.C., especially at night." He used to drive a night run from Virginia to Union Station, and said that in the city there is more "disregard of the rules" forbidding smoking and eating. "Drivers over there get hassled more" and take "more verbal abuse."

On the 24E bus, he says, the riders "just want to get to work."