Watch how the traffic shifted on McHenry Avenue Bridge over Stanislaus River
Demolition has begun on the old McHenry Avenue bridge over the Stanislaus River that connects San Joaquin and Stanislaus counties.
The eastern half of the replacement bridge opened April 27, carrying both northbound and southbound traffic as the old bridge is torn down and the rest of the new span is built.
Demolition could last between three and six weeks, said Michael Selling, San Joaquin County deputy director of engineering with the Department of Public Works. The timing is up in the air because a fiber-optic communications line that runs through the old bridge structure has to be relocated, he said.
In a recent news release on the bridge, which is part of the Improve McHenry Avenue project, San Joaquin County Public Works Director Kris Balaji said, "It’s a bittersweet moment as the temporary shift on the new structure signals the demolition of the existing bridge, which proudly served the public for 59 years.
"The inevitable onset of structural deterioration and the lack of space to meet future traffic demands requires the torch to be passed down to a new and improved bridge."
The 1959 bridge was 30 feet wide, and the eastern half of the new bridge already is 3 feet wider than that. When the full bridge opens in the summer of 2020, it will be more than 75 feet wide and will include a sidewalk and 5-foot paved shoulders to accommodate bicyclists.
In designing the McHenry improvements, engineers did traffic projections 20 years out, using what's in the Modesto, Riverbank and county general plans, Selling said. It's always a Catch-22 situation, he said, to design to accommodate growth without inducing it.
Looking at counts for the intersection of McHenry Avenue and River Road, just north of the river, the average daily traffic in 2011 for McHenry was about 10,000 vehicles, and for River about 4,000, Selling said. Now, the numbers have grown to 14,000 and 6,000.
Traffic congestion already had been eased with a temporary roundabout, dubbed a “bean-a-bout” because of its peanut-like shape, at the intersection.
The bean-about was scheduled for removal during construction to accommodate work zones. But public feedback on it was so positive that the project team simply modified it to a traditional roundabout. When the McHenry project is completed, there will be signal lights at the River Road intersection and "turn pockets" that will break up and ease the traffic flow, Selling said.
Maybe a decade ago, when planning for the intersection was in early stages, traffic engineers considered a roundabout as the way to go instead of signals, Selling said. But there's a South San Joaquin Irrigation District canal north of River Road, and to accommodate traffic growth, the roundabout's "footprint would have been so big it would have required moving the canal, which was cost-prohibitive."
Modesto commuter Kevin Towns likes what he's experienced so far. "I drive it almost every day coming back from Stockton in the afternoon," he commented on Facebook. "It seems to be working out pretty well, as far as I’m concerned. Sometimes I notice the traffic heading north out of Modesto at that time is backed up approaching the bridge."
In a news release, San Joaquin County Board of Supervisors Chairman Bob Elliot said the benefits of the McHenry project are tremendous. "Though the McHenry Avenue bridge is one of only three Stanislaus River crossings in the area and directly connects Escalon and Modesto, the project reaches beyond San Joaquin and Stanislaus counties," he said. "It will provide a safer and more traffic-efficient corridor for decades to come.”