If rush hour in Santa Rosa seems more congested than normal, it is.

But not because there are more cars on the road.

It seems the city's super-smart network of traffic signals dropped a few IQ points last month.

A software program that coordinates the city's traffic signals seized up when a computer server and its backup both crashed March 23.

This forced signals at major intersections to revert to a dated program that isn't nearly as efficient as the current one, said city traffic engineer Rob Sprinkle.

"It's definitely noticeable," Sprinkle said. "If you're driving on some of the major corridors, the timing is different than it had been two weeks ago."

One of the hardest hit areas is Guerneville Road and Steele Lane near Highway 101. With arteries already clogged by In-N-Out Burger on the east side of the freeway and construction at Coddingtown Mall creating detours on the west, the area was already one of the city's most choked.

But in recent weeks, traffic has gotten noticeably worse, said Santa Rosa Ski and Sports owner Carole Holley.

"Now it's awful getting through there," declared Holley, who said it can seem like it takes a half-hour to navigate the area at lunchtime.

Sprinkle said city technicians have been working hard to get the system up and running again and are "cautiously optimistic" it will be online this week.

"We know it's a problem. We know it's an issue, and we're working on it," Sprinkle said.

The city's "adaptive traffic control system" is installed on major traffic corridors around the city. The main routes include College Avenue to the south, Stony Point Road to the west, Guerneville Road and Steele Lane to the north and Mendocino Avenue to the east. At intersections in these areas, pole-mounted cameras monitor traffic, largely replacing the in-ground sensors that for decades detected vehicles.

The cameras now feed real-time data to a software program that automatically adjusts the cycle lengths of signals to prevent traffic back-ups. It can also coordinate signals at surrounding intersections to keep traffic flowing smoothly, Sprinkle said.

When the server that housed the software program crashed, the backup files were also corrupted, Sprinkle said. So instead of just rebooting the program on a new server, city staff have spent two weeks essentially rebuilding it, he said. He estimated the fix is 95 percent complete.

In the meantime, the traffic lights have reverted to an older system of signal cycles set for certain times of day. Those backup cycles are a little out of date, however, making them less effective than they once were, he said.

The system isn't flying totally blind, however. The cameras still work and continue to trip the signals when vehicles are detected, Sprinkle said.

The system was installed in three phases beginning with College Avenue in 2007. It has cost about $3 million, with $2.1 million coming from grants and the $800,000 balance from local funds, Sprinkle said.

State and federal grants funded such projects in many cities in large part because reducing the amount of time cars and trucks sit idling in traffic was seen as a way to reduce greenhouse gas emissions.

In a way, the traffic problems created when the system went down shows how necessary it is, Sprinkle said. "We don't want it to go down, but when it does it validates that it's taking care of a lot of the traffic."