The lives of pedestrians — and bicyclists — in Manteca do matter.
Manteca’s elected leaders have put in motion a series of projects aimed at enhancing the safety of pedestrians and bicyclists in the coming years as traffic continues to increase on city streets.
uLast month the council hired an engineering firm to design a separate pedestrian/bicycle bridge crossing in conjunction with the new diverging diamond interchange being planned for Union Road at the 120 Bypass. The project could cost $1.5 million.
uThe council approved a capital improvement plan that calls for the Wellington Avenue pedestrian crossing on Woodward Avenue to be upgraded to the same improvements as are now in place on Woodward Avenue at Buena Vista Drive. That project will cost about $150,000.
Smaller projects moving forward in the coming months includes rumble strips around select school campuses as part of city street maintenance as well as bicycle lanes in the 100 block of North Main Street as part of the $1 million bulbout removal project.
“The council has clearly made pedestrian safety a priority,” noted City Manager Karen McLaughlin.
The city’s focus on enhancing pedestrian safety when possible came on the heels of three pedestrian deaths over 18 months — a grandfather who was pushing his grandson in a stroller across Woodard Avenue, a first grader walking to Shasta School, and a man struck crossing Center Street in mid-block.
The city has also established an ongoing working relationship with Manteca Unified to address students’ safety walking to and from school following the death of the first grader last September.
The rumble strips are an outgrowth of those discussions as is city staff reviewing signage around certain elementary schools to determine if more are needed. The most recent request involves signs for traffic approaching Cowell School on Pestana Avenue.
The decision to build a separate bridge for pedestrians and bicyclists at Union Road over the 120 Bypass will mean they won’t have to cross on and off ramps that are being designed to move more vehicles as part of a diverging diamond design.
Originally staff had proposed directing pedestrian and bicyclist into a path in the middle of six lanes of traffic protected by railing or concrete K-rail — in order to cross the 120 Bypass as part of a diverging diamond design. That would have required bicyclists and pedestrians to cross traffic four times to get across the 120 Bypass.
There are diverging diamond designs that keep the bike lane and sidewalk or separated bike path for bicyclists and pedestrians to share on both sides of the crossing. In doing so, pedestrians and bicyclists are left to cross traffic turning into and off the freeway without protection of traffic lights. If traffic lights were added it would defeat the purpose of eliminating stops for vehicles and not increase the volume that the ramps could handle.
How a diverging
diamond design works
Manteca is pursuing a diverging diamond interchange for Union Road instead of upgrading the existing structure to a partial cloverleaf.
Traffic lanes cross on either side of the bridge structure of a diverging diamond interchange so northbound traffic would cross the bridge on the west side instead of the east side with the southbound lanes on the east side instead of the west side. Once they clear the bridge they are switched back.
The on and off ramps along with the flipping of the lanes creates two semi-diamond shaped intersections on either side of the bridge. This eliminates the need for traffic from both directions on Union Road as well as that coming from the 120 Bypass needing any traffic signals to exit an off ramp or to get into an on ramp. The project will also include ramp meter signals such as now are in place on the Lathrop Road/Highway interchange.
The design could slash as much as $10 million from the $25 million estimated cost of converting Union Road into a partial cloverleaf.
The new overpass is being funded with money collected from growth as well as unspent redevelopment agency funds that were earmarked for the Union Road project.
Other advantages of a diverging diamond interchange according to Advanced Transportation Solutions/American are:
uFewer conflict points (14 for diverging diamond design, 26 for conventional design).
uBetter sight distance at turns.
uTraffic calming features when desired.
uAdditional right of way is rarely needed.
uVirtually no driver confusion based on a study and observation of existing diverging diamond design interchanges.
uConstruction time is reduced.
uWrong way entry to ramps extremely difficult.
uPedestrian crossings are shorter.
uMaintenance of traffic is simplified during construction.
There are 57 such interchanges now in place in the United States. The closest is in Reno on Interstate 580 at Moana Lane.
To contact Dennis Wyatt, email firstname.lastname@example.org