North Texas' struggling Dallas Area Rapid Transit bus system is going to get a massive overhaul. But it's going to trickle out over years, even though DART has been working to speed things up.

DART bus ridership dropped from 121,999 bus riders on an average weekday in 2015 to 113,095 in 2016. The downward trend has continued into the first few months of this year.

Blame for the declining ridership has fallen on everything from a rebounding economy where more people can afford to drive, to changing housing patterns where fewer bus-dependent workers live on outdated bus routes. Some existing bus routes have never had a lot of traffic, and they exist as relics of past well-intentioned efforts to provide service where it turns out few people really needed it.

Either way, the result is the same: Many buses just don’t run when and where riders need them.

“DART has to make sure the core ridership is focused on ... so they can get from their home to work, schools or hospitals in a timely fashion,” new DART board member Ray Jackson said last month. He told the Dallas City Council’s transportation committee low-income riders need a system that works better for them.

Customers and city officials have long complained about routes where the buses don’t travel the lines often enough and take hours to get them where they need to go. The problems are primarily in areas south of Interstate 30 where more people depend on public transportation.

The agency developed a comprehensive overhaul plan in 2014 and began to trickle out changes the following year with off-peak frequency improvements and bus connections to the Rowlett DART rail station.

Central to the overhaul is a long-term plan to create a “core frequent route network” which would make buses run on their routes every 15 minutes or better during peak travel times, every 20 minutes or better during the midday and every 30 minutes or better on weekends.

The agency also hopes to make some routes more direct, eliminate low-performing routes and expand the availability of weekend service.

But those changes require more buses and may be years away. Many customers and Dallas City Council members say they want bigger changes sooner.

The Dallas City Council voted unanimously last fall to make overhauling the bus system a top priority. That decision was cited in a recent effort to replace several of the city's DART board representatives.

Four new DART board members — Catherine Cuellar, Dominique Torres, Ray Jackson and Jon-Bertrell Killen — were named earlier this month. Each said they’d push hard to fix the bus network. And board member Patrick Kennedy, who started his term in January, told the council's transportation committee last month that he has been working closely with DART staff on issues plaguing the bus system.

While speaking before the council’s transportation committee last month, Kennedy said he hopes to add more buses to improve frequency, but there are also inefficiencies in the system that can be worked out, like duplicate services and buses running on the same routes as rail.

“If we start heading more toward a gridded system, there is an opportunity for more intuition to be built in the network,” he said.

DART officials say they’re working to speed up their long-term plans.

In August, DART will begin tinkering with bus routes that currently have poor on-time performance, mostly during the middle part of the day. Those changes will focus on off-peak times for now because the agency is awaiting the delivery of about 41 new buses.

“You can’t improve frequency on peak hour buses if you don't have enough buses,” said Todd Plesko, DART’s vice president of planning and development.

“What we realized was, we could improve the midday frequency without buying more buses, so we are accelerating some of the changes that we anticipated doing in August 2019, and we are going to push them up into March.”

If the August changes go ahead as planned, the frequency of buses running along some routes would change from every hour to every 45 minutes on Saturday and Sunday.

Buses would also run more frequently during some weekday off-peak hours. For example, on Route 521, which travels from Mockingbird Station to Northwest Highway at Hillcrest Road, buses would run every 45 minutes rather than every hour.

The next round of proposed service changes is planned for March, pending board approval. On Tuesday, the DART board’s planning committee will be presented with details of those changes. The entire board would consider them later this year after a series of public hearings.

Plesko said the March changes would be larger and more extensive, potentially including the elimination of several routes so that those buses could be diverted to improve frequency in other areas or for a pilot project to bring service to customers living in less dense, less served areas.

The biggest changes could still come in August 2019. By then the new buses should be in service and DART would be able run buses more often on some of its lines during peak hours.