Downtown traffic has been one of the most debated and studied issues in Manteca during the past 50 years.

Everyone seems to have an opinion on what to do - or not to do - about traffic on Main Street and Yosemite Avenue as it passes through the central district. The reason why it is an issue is simple. There is a perception that how traffic slows and plenty of on-street parking are critical to the economic health and vitality of downtown. Also there is the issue of congestion where traffic at certain times on Saturday and during weekdays will back up for two blocks or more on Main Street especially southbound.

It may seem like Yosemite and Main is the busiest intersection in Manteca but it’s not. Based on the last daily average traffic count survey done in 2009, Yosemite-Main was the seventh most congested intersection in Manteca with 24,800 vehicle trips a day. The runaway No. 1 intersection is Louise Avenue and Main Street with 37,700 vehicles a day.

The reason why Yosemite-Main is congested and Louise-Main isn’t is the number of lanes. Louse-Main has two thru lanes plus dedicated left turn lanes in each direction plus the ability to make right hand turns away from the thru lane. The narrower Main Street through downtown constricts flow. And Yosemite Avenue - still the major east-west commercial street in Manteca - is also just two lanes through the center of town.

For traffic flow - if that is determined to be the superior priority - the solution revolves around increasing capacity. To duplicate the flow at Louise and Main - businesses on one side of both Main and Yosemite Avenue would have to be razed through downtown. That isn’t a practical solution

One solution that keeps popping up every seven years or so triggering an earnest study is converting Yosemite Avenue and Center Street into one-way traffic.

It was first advanced in the 1970s by Caltrans when Highway 120 went down Yosemite Avenue and weekend traffic backups for miles from Bay Area traffic going to and from the Sierra made today’s congestion seem like free flowing traffic in comparison.

Originally, Highway 99 and Highway 120 crossed at Yosemite and Main. The Highway 99 freeway opened in 1955 eliminating one source of congestion. But Highway 120 traffic grew as the Bay Area grew. There were times on Friday nights traffic would snake into Manteca at 10 mph or less all the way from the Mossdale bridge on the San Joaquin River.

Caltrans proposed making Yosemite Avenue for eastbound traffic only from Union Road to Powers Avenue. The state also proposed making Center Street westbound from Powers to Union. That plan, however, would have required taking out a number of homes. It never got much traction.

When the 120 Bypass was built in the 1980s it eased Yosemite Avenue significantly but as the city grew the traffic issue popped up again.

The plan surfaced again at least four times since then with a serious enough push that the one way plan was debated, studied, debated again and shelved.

The subsequent versions had one-way traffic between Union Road and Fremont Avenue on both streets.  The estimated price for such a conversion including some minor property acquisition and modifications to intersections, lane, signs, and traffic signals was estimated at $700,000.

The most recent full-scale debate produced the decision to convert the 100 block of North Maple Avenue into a one-way southbound street.

That move reduced congestion at Center and Main from motorists trying to reach the Post Office. The biggest benefit though was the elimination of traffic backups on eastbound Yosemite Avenue that stretched across the railroad tracks at times from motorists trying to turn left onto Maple Avenue.

Maple Avenue is Manteca’s second one-way street. The other is just a little over a block away to the west where Pierce Avenue - about six car lengths long runs between Manteca Avenue and Yosemite Avenue.