Trains still rumbled through the city on the Union Pacific tracks parallel to First Street on Monday, but there was something noticeably different about the way they did so. Many of the trains didn’t sound their horns.

After decades of sounding deafening horns, many engineers began observing a Quiet Zone that encompasses five train crossings along First Street.

The crossings are at Hamilton Boulevard, Park and San Antonio avenues, and Main and Palomares streets.

Pomona officials believe this is the first Quiet Zone in Los Angeles County.

In a Quiet Zone, engineers refrain from sounding their horns unless they spot a person or vehicle so close to the tracks that they present a safety hazard.

In such cases, engineers can still sound their horns, said Councilman George Hunter on Monday.

Hunter, who worked to secure the Quiet Zone as the city’s representative to the Alameda Corridor East Construction Authority, said the silencing of the horns will make a difference to many living or working near the crossings.

"It’s going to be a big quality of life improvement," Hunter said.

The Quiet Zone is going to help residents, businesses and others along the corridors by providing a more tranquil environment, Hunter said.

It’s also going to benefit residents who move into future downtown housing developments planned for the area, he said.

Some people have lived with the horns so long they don’t really notice them, Hunter said. For those who haven’t blocked them out, "it’s one less intrusive element" to contend with in an urban environment.

While the Quiet Zone will provide some relief immediately, its benefit will be much more critical with time, Hunter said.

"(It will be) much more pleasing in the long term because train traffic is going to continue to increase in the next 10 years," he said.

Transportation agencies forecast longer trains will be traveling through the area more frequently in the years to come.

For Hunter, the Quiet Zone represents the culmination of an effort that took years and which began under the tenure of the late Mayor Eddie Cortez while he represented the city before the Alameda Corridor East Transportation Authority.

City administrators had hoped to have the Quiet Zone in place early last month.

The Quiet Zone appeared to have the support of Federal Railroad Administration officials but the California Public Utilities Commission had some concerns that were addressed in a meeting organized late last month.

Officials from the Federal Railroad Administration, the state Public Utilities Commission, Metrolink, Union Pacific and others participated in the meeting, Tim D’Zmura, Pomona’s city engineer/public works director said last week.

After the meeting city administrators were "cautiously optimistic" that the Quiet Zone would be implemented, D’Zmura said. At least some neighbors noticed the absence of the horns Monday.

Students, faculty and staff at Western University of Health Sciences were talking about the significant reduction in train horns.

"We’re delighted to hear the city of Pomona has worked so diligently to get a final disposition on the horn issue," said Dereck Andrade, executive director of public affairs for the university.

The back of some of the university’s buildings are just yards away from the train tracks and in its 30 years of existence, the horns have at times drowned out speakers at special events, Andrade said.

Still the university community has understood the horns were a part of ensuring driver and pedestrian safety, he said.

The city took a series of steps, including adding signs, constructing medians and restriping streets to qualify for the zone.

And a major element in the establishment of the Quiet Zone involved the Alameda Corridor East Construction Authority’s installation of four-quadrant gates at all five train crossings at a cost of $3.7 million.

The specialized gates prevent cars from getting near the tracks when a train is approaching. The gates have have sensors that keep vehicles from becoming trapped between the arms.

Andrade said he was in an informal meeting in his office Monday morning when he realized a train was passing through the area but wasn’t sounding its horn. His office a short distance from the tracks.

After excusing himself from the meeting Andrade headed outside and saw a train rolling by at a somewhat slower clip than usual and without blasting its horn, he said.

"I’m standing in the parking lot staring at this train," he said "I couldn’t believe it."

Andrade joked that a few people stared back as he stood in watching the train in disbelief.

Not all train conductors have received notification about the Quiet Zone, however.

Andrade said shortly after watching the eastbound train pass by a westbound train charged through as usual.

"It was blowing (its horn) like there’s no tomorrow," he said.

Hunter said it will take some time before all engineers are informed the Quiet Zone must be observed.

Staff writer Monica Rodriguez can be reached by e-mail at m_rodriguez@dailybulletin.com, or by phone at (909) 483-9336.