Q: During commutes from Snohomish County to South Seattle and then to the Eastside, Roger Harlow, who lives in Lake Cavanaugh, southeast of Mount Vernon, has been struck by the number of "out of service" Metro buses he's spotted in the far-left "fast" lane headed towards the Eastside on Interstate 90. He's wondered why so many buses make the trip empty, and why at some of the busiest times of the day?

To be sure, he's not alone in asking such questions.

Harlow's dad was a transit employee here for nearly four decades, he said. "So I understand the repositioning of buses for different routes." His gripe, though, is that so many buses travel the freeway slower than the posted speed in that left lane. "And as I pass them in the right lanes, I notice that the drivers are not in any Metro Transit uniform. They are in mechanic's coveralls."

Harlow suspects it's a mechanic taking a bus out for a test drive in the middle of rush-hour traffic, clogging up the freeway's fast lane. "This kind of activity needs to be scheduled for off-hour and maybe a route other than the freeways," he said.

And even if those times are because it's during that driver's normal shift, that's not enough reason, he says, to hold up traffic unnecessarily.

A: It's not unusual for Metro Transit's vehicle maintenance folks to drive buses between bases and to and from other Metro facilities, said agency spokeswoman Linda Thielke. "Sometimes it's moving buses base-to-base where there may be a short-term need at one base. Sometimes, the buses are being moved between the main body shop in Tukwila and back to the bases. There could also be the occasional test run either after repairs or trying to troubleshoot a specific problem where you need freeway speeds or conditions to check it out."

Recently, drivers on two Seattle-Renton routes reported problems with their coaches at higher speeds on eastbound Interstate 90. Thielke said vehicle maintenance staff tried to simulate those conditions with empty buses to pinpoint a problem. That may have been why Harlow spotted empty buses in the left lane, "because that's where those buses usually travel," said Thielke, "and they wanted to see if the road conditions had anything to do with the problems the drivers were reporting."

Nonetheless, Metro isn't convinced their buses are clogging up the freeway, said Thielke. Buses don't always have to return to base to switch drivers. Sometime drivers rendezvous with a bus at a designated point, using a county car to get there, then switching off with the driver being relieved, she said.

Q: If you've been keeping up with local news, you've probably heard or read that Washington State Ferries has troubles on its hands with the system's four Steel Electric Class boats.

Simply put, the 80-year-old vessels' hulls are falling apart.

So, have those vessels been running all these years on electricity? Why, asked Charles Reed of Kenmore, are they known as Steel Electric Class ferries?

A: For one thing, the hulls are made of steel. For another, those boats are powered by diesel electric propulsion. The diesel engine turns a generator which produces electricity. That electricity is then fed to a motor which turns the propeller, according to ferry folks.

Longtime ferry historian David Black of Poulsbo, himself a former ferry employee, says there was a class of wooden boats called the wooden electrics, and when new boats were made of steel and had a diesel electric engine, they became the steel electrics. Simple enough?

The ferry system's four troubled boats — Illahee, Klickitat, Quinault and Nisqually — were some of the oldest ferries still in service. They've been in the fleet here since the 1950s.

Q: If you drive a sporty two-seat coupe, like, say, a Nissan 350Z, with only yourself and one passenger, how legal would you be in a carpool lane that requires at least three people? "I heard that driving in a three-person carpool is legal with only two people if your car only seats two," wrote Aaron Brooks of Duvall. "Is this true?"

A: The truth is, no, it is not legal for a two-seater vehicle to use HOV lanes that require at least three people, such as westbound on Highway 520, says Leah Bolotin, senior HOV planner for the state Department of Transportation.

The three-plus requirement applies to 520's westbound carpool lane between Interstate 405 and the Evergreen Point Floating Bridge, and the state says the reason is to improve traffic flow.

Motorcycles are permitted by federal law to travel in all carpool lanes because it is considered safer to keep two-wheeled vehicles moving than to have them traveling in start-and-stop traffic. But that has nothing to do with how many people the motorcycle is designed to carry, says Bolotin.

The state has concluded that the HOV lane on that limited stretch of Highway 520 cannot safely carry the kind of traffic that other carpool lanes do. (Bolotin says the lane was created in the 1970s from the outside freeway shoulder in order to allow buses to bypass toll booths on the bridge at that time.)

The lane is narrow, has no shoulder and handles merging traffic from on- and off-ramps. "To keep drivers safe, we limit the amount of traffic in that lane by only allowing vehicles carrying three or more people," Bolotin said. The restriction also helps reduce congestion at the point where the carpool lane merges back into general purpose lanes just before the bridge.

That location is a real bottleneck, says Bolotin, "and every additional vehicle forced to merge into the two lanes crossing the bridge causes longer backups for everyone."

So, the DOT weighed having a consistent 3-plus carpool lane for the length of Highway 520, or allowing 2-person carpools in places. "After consulting with local communities, we agreed that it would be better to get full use of the HOV lanes east of I-405 by allowing 2-plus carpools where it is safe to do so," she said.

As part of the Highway 520 bridge replacement and carpool project (www.wsdot.wa.gov/projects/SR520Bridge), the DOT says it will rethink the carpool situation. "Once this project is complete, we may be able to reduce the occupancy requirement to two people," said Bolotin. "We will decide whether to make a policy change after looking at the amount of traffic and the conditions on the rest of the freeway system."

Q: This week's rain deluge has been rather unusual. But Kevin Kilpatrick, who lives along Ravenna Avenue Northeast, says there's always water on the roadway in his neighborhood, particularly in the intersection at Northeast 86th Street and Ravenna. And when the mercury drops, he's noticed that the northbound lanes of Ravenna from 86th to 90th are iced over because of the water.

"The water isn't going away," he said. "So why aren't there signs warning of the ice danger?"

There was an accident not too long ago, he said. "Someone wiped out on the ice and struck a few parked cars."

Kilpatrick suggests signs that would turn blue when it's freezing.

A: That water is probably coming from natural springs, says Wayne Wentz, the Seattle transportation department's traffic management director. That area has some, and there are a lot of springs around the city.

Ground water springs are not normally controlled, since they can spring up randomly, Wentz said. Seattle's drainage system captures surface water from roadway runoff into the nearest drainage inlet.

Wentz said staffers from his department visited that area recently, joined by Seattle Public Utilities and others. To help solve the problem, Wentz says a maintenance crew will clean up the road shoulder and install an asphalt berm to direct the ground water to the drainage ditch.

"I have alerted both day and night supervisors to check this area under freezing conditions," he said.

If it seems to passersby that the roadway needs sanding, call the transportation department's street maintenance dispatcher at 206-386-1218. That phone line is supposed to be staffed around the clock.

"We believe these two measures will address the drainage and ice concerns," said Wentz. However, he's not so optimistic about additional warning signs that change colors when the temperature drops.

Q: On a Saturday afternoon not too long ago, Mike Nesteroff of Bellevue came upon Highway 520's Evergreen Point Bridge being opened for boat traffic. That was about 1:30 p.m. The Sunday before that, he came upon the bridge being opened about 3 p.m.

"I don't recall the bridge opening, except at very off-hours like late at night or very early in the morning on weekends," he said.

The Saturday opening was particularly untimely, he said, because it takes about a half-hour to open and close the bridge, and that particular opening was at the height of traffic on a UW Huskies game day, "backing up cars all the way to Interstate 405 westbound and onto Interstate 5 eastbound, all for a single sailboat to go through.

"What's the deal?" he asked.

A: In general, federal law gives marine traffic the right-of-way over vehicular traffic. However, the Coast Guard can grant exceptions for bridge closures during rush-hour periods, so the Highway 520 bridge is not usually opened for marine traffic between 5 a.m. and 9 p.m. weekdays, said state Department of Transportation spokeswoman Meghan Soptich.

Even so, the bridge can be closed to vehicle traffic for a drawspan opening at any time on weekends or federal holidays. Boaters must schedule openings at least two hours in advance.

"We do our best to notify drivers about drawspan openings by posting warnings on our electronic message signs on Highway 520, I-5, I-405 and I-90 at least a half-hour before a scheduled opening so drivers can choose alternate routes to get to their destinations," Soptich said.

But even if it is just one sailboat, if the boat's mast is too tall for the drawspan, the bridge can be opened, regardless of the amount of traffic on the bridge.

You can read more about when and why the state closes the Evergreen Point Bridge to vehicle traffic on the DOT's Web site: www.wsdot.wa.gov/traffic/bridges/sr520/whyclose.htm.

(P.S.: The above item, posted in The Bumper Connection on Dec. 4, (and in Bumper to-Bumper in print and online on Dec. 10), attempted to explain the why and when Highway 520's Evergreen Point Floating Bridge is opened for marine traffic, disrupting traffic on the bridge. It happens from time to time.

Yes, that floating bridge's drawspans slide to the side. Either way, though. bridge openings still disrupt bridge traffic. )