Sep. 21--On South Park Avenue, just south of East 36th Street, there's a speed-bump-size lump of asphalt across the road. Drivers have to slow down to ease over the lump mere feet from the south side of the intersection.

It seems out of place for a major roadway, but it's part of a sewer project on the southeast corner of the intersection.

I asked Pima County Public Works for details. Here's a summary of the answers to my questions from Nancy Cole, the project manager:

What is the construction project on the southeast corner of South Park Avenue and East 36th Street?

The county is installing a new sewer line to upgrade the capacity for the area. The work will replace a 36-inch-diameter sewer line with a 42- to 48-inch line. The new lines connect into the southeast interceptor line, which runs parallel to Interstate 10. Those lines connect with the Santa Cruz interceptor, which takes sewage to the Roger Road Wastewater Treatment plant.

How long is the project supposed to last?

Construction started in July; it is scheduled to last one year.

Why is there a big bump on Park, south of the intersection?

The bump is caused by a sewer bypass. In order to work on the sewer lines, the sewage has to be rerouted around the construction area so service isn't interrupted.

Why can't the bypass lines be buried so they don't affect traffic?

There are two ways to do a bypass. The preferred method is to bury the new pipe and let gravity carry the waste to the main line. But that works only when the distance and slope are enough for gravity to do its work. In this case, it wasn't an option. This work-around is the second-best option, and it requires a pump to get everything moving in the right direction. The pump is what's causing the speed bump at the intersection.

How long will the bump be there?

The pump-around is needed for about 60 days. Drivers can expect at least another month before it's gone. "The key thing is we ask for patience while we do it," Cole said. "We have to be really very careful about working with sewer lines, and that's why we have to go this extra step of doing the rerouting. We hope to be in and out in as timely a fashion as we can."

Road Q

Question: "On Congress (Street) westbound -- in front of the health and welfare building, just underneath the pedestrian overpass downtown -- there are four two-hour meters. In the same parking spots, there are loading signs limiting parking to only 20 minutes. Now when people park there and feed the meter for the full two hours, they are also ticketed for parking in a loading zone. This doesn't make sense. How can you put two-hour parking meters in spots where you'll get ticketed for parking more than 20 minutes?" Tony Martinez wrote.

Answer: Tony's right -- that doesn't make sense, which is why the spots are regulated differently based on the time of day. Three signs near the four parking spots say the two-hour metered parking is for 8 a.m. to 4 p.m. Mondays through Fridays. From 4 to 6 p.m. Mondays through Fridays, the spots are for 20-minute passenger loading only. Right outside of several county offices, "we're trying to encourage car pooling in those spots," said Chris Leighton, the city's parking program coordinator.

Road Runner answers road-related questions in this column on Mondays. Find Road Runner, plus traffic cams and other transportation news, at azstarnet.com/ transportation. Send your questions by e-mail to roadrunner@azstarnet.com or to P.O. Box 26807, Tucson, AZ 85726. Please include your first and last names.

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