Living next to downtown Palo Alto's bustling train station has many benefits, but for residents of 101 Alma St., a good night's sleep isn't one of them.

Douglas Cardwell said the number of children who live in the building has gone up markedly in the past decade, with about 25 currently inhabiting the building. But it's not the children who keep Cardwell awake at night but horns from the passings trains, a sound that has become a little too familiar to him and his neighbors in recent years.

On Monday, Cardwell joined his neighbors in asking the City Council for relief. The city, he and his neighbors said, should try to establish a "quiet zone" near the downtown station, a designation that needs an approval from the Federal Railroad Administration.

The designation effectively waives the requirement that trains sound their horns at least 15 seconds (and no more than 20 seconds) before approaching a public grade crossing. The volume must be at least 96 decibels and no more than 115, according to the Train Horn Rule adopted in 2005.

Federal regulations specify that train conductors must use the familiar pattern of two long horns, one short horn and one long horn to signal their approach. That, however, doesn't always happen, said Nancy Larson, who also lives at 101 Alma. In some cases, the train operators like to do "a little staccato" as they enter the crossing. She said she recalled watching a train pass her house and blowing the horn seven times.

"No one tells them what to do," said Larson, whose apartment overlooks the rails.

In recent weeks, residents of 101 Alma and their neighbors have been researching how to establish quiet zones and lobbying the council to create one on Alma. A petition recently launched by resident Zouhair Mahboubi calling for a quiet zone has received 127 signatures as of Tuesday morning. The petition calls train horn noise a "significant community issue" and notes that the required noise level is "very loud, and with freight trains running throughout the night, many residents struggle with sleep."

Establishing a quiet zone would "greatly improve the quality of life by reducing noise pollution in Palo Alto, while still providing a safe crossing and at no significant cost to the city," the petition states.

On Monday night, Mahboubi brought his case to the council and secured a commitment that city staff will explore that issue. Creating such a zone will not be too onerous or expensive, Mahboubi said. Federal regulations set out the process and criteria for such zones, including a requirement that such a zone be at least half a mile in length and that certain safety measures be put in place. The measures, which would have to be approved by the FRA in advance, could include such things as wayside horns, signs or closure of crossings.

Mahboubi's presentation came shortly before the council was set to discuss a far more ambitious proposal for the Caltrain tracks: the digging of a trench along the corridor in south Palo Alto. While that project comes at a cost of $1 billion (or $488 million, if the trench is built under a steeper grade), creating a quiet zone would be much cheaper and easier, he said. The group believes the crossing already has enough safety measures to enable the creation of the quiet zone with "little to no construction," he said.

"Here we present to you an opportunity to make within a very short term a very huge impact on a big community," Mahboubi said.

Mahboudi noted in a letter to the council that he and his neighbors have already relayed their concerns to Mayor Nancy Shepherd and senior staff. On Monday, City Manager James Keene said city planners will continue to work on exploring the issue of establishing a quiet zone.

"Our planning staff is attuned to this issue and has already met with some of the folks on this matter and we will continue to meet with them to explore this matter further," Keene said.