After nearly a century of service, the northern portions of the Red and Purple lines have outlived their predictable useful service life, according to the Chicago Transit Authority.

The CTA proposes to make improvements on both lines, which together provide an average of 128,000 rail trips per weekday to neighborhoods along the north lake shore.

The Red and Purple lines were constructed from 1900 to 1922 and, according to the CTA, carry more than 19 percent of all CTA passengers on weekdays and 23 percent on weekends.

“A lot of the infrastructure is very old,” said Michael Connelly, manager of Program Development at CTA. “They really need to be replaced.”

The proposed plan will take approximately eight years to complete, according to the CTA.

The CTA and Federal Transit Administration have worked with the National Environmental Policy Act, which requires federal agencies to incorporate environmental values into their decision-making process.

During the last year, the CTA has been preparing a Tier 1 Environmental Impact Statement for the modernization of both lines, which is an extensive outline of general issues and overall impact of the CTA.

A yearlong CTA study provided community feedback leading to six options. These range from a no action alternative, which means keeping the system as is, to basic structural maintenance that would provide enough service for the next 20 years, to taking various elevated lines from both Red and Purple lines and turning them into a subway.

“This is all preliminary,” said Catherine Hosinski, media representative for the CTA. “There are six options that were developed based on the community feedback we received at a meeting we held in 2009.”

The other options consider combining stations. According to CTA, there is a possibility of closing the Jarvis, Thorndale and Lawrence stations on the Red Line, and the South Boulevard and Foster stations on the Purple Line.

“We are very early on in the process—nothing is finalized,” Connelly said. “We are beginning the environmental process, and it’s not just strictly environmental in the sense of air quality—it’s noise, congestion and impact on people who live in the neighborhoods.”

According to the CTA, an estimated $4 billion would address the three most expensive proposals that would fully repair all accessibility concerns.

Currently, only six of the 21 stations north of Belmont are handicap accessible. Hosinski said in order to provide accessibility for both lines, funding needs to be identified.

The $2.9 billion and $2.4 billion plans, according to the CTA, include improvement but would tackle only some accessibility concerns.

The cheapest plan is called the “no action alternative.” According to the CTA, it would maintain the “status quo” and make minimum repairs to keep both lines functional.

“People told us what they wanted, such as safer environments and better lighting,” Connelly said. “We went back over the past year and did bridge engineering studies and we came back with alternatives.”

A community meeting was held in the 49th Ward at New Field Primary School, 1707 W. Morse Ave., on Jan. 26. James Snyder, a community member who attended the meeting, said he thinks some of the repair options for the station awnings are irrelevant to helping passengers.

“They need to expand protection for the passengers,” Snyder said. “It’s a wasteful expense to expand the awnings; it’s engineering stupidity.”

Although no final decisions have been made, the CTA is prepping alternative options to get the community talking.

Connelly said the goal for this proposed plan is to make all of the stations assessable.

“The process for this project is to move forward as a community,” he said.

“This is all preliminary,” said Catherine Hosinski, media representative at the CTA. “There are six options that were developed based on the community feedback we received at a meeting we held in 2009.”

The other options consider combining stations. According to the CTA, there is a possibility of closing the Jarvis, Thorndale and Lawrence stations on the Red Line and the South Boulevard and Foster stations on the Purple Line.

“We are beginning the environmental process, and it’s not strictly environmental in the sense of air quality—it’s noise, congestion and impact on people who live in the neighborhoods,” Connelly said.

According to the CTA, an estimated $4 billion would address the three most expensive proposals that would fully repair all accessibility concerns.

Currently, six of the 21 stations north of Belmont are handicap accessible. Hosinski said to provide accessibility for both lines, funding needs to be identified.

The $2.9 billion and $2.4 billion plans, according to the CTA, include improvement but would tackle only some accessibility concerns.

The cheapest plan is called the “No Action Alternative.” According to the CTA, it would maintain the “status quo” and make minimum repairs that would keep both lines functional.

“People told us what they wanted, such as safer environments and better lighting,” Connelly said. “We went back over the past year and did bridge engineering studies and we came back with alternatives.”

A community meeting was held in the 49th Ward at New Field Primary School, 1707 W. Morse Ave., on Jan. 26. James Snyder, a community member who attended the meeting, said he thinks some of the repair options for the station awnings are irrelevant.

“They need to expand protection for the passengers,” Snyder said. “It’s a wasteful expense to expand the awnings; it’s engineering stupidity.”

Although no final decisions have been made, the CTA is prepping alternative options to get the community talking.

Connelly said the goal for this proposed plan is to make all of the stations accessible.

“The process for this project is to move forward as a community,” he said.

kfranzen@chroniclemail.com