SEPTA's trolleys haven't been replaced since the 1980s when Ronald Reagan was president, yet they are wildly popular with their 100,000 riders who squeeze into them every day. Thankfully, the transit agency wants to replace them with bigger cars which can handle roughly twice as many passengers per car than the 75 they can now and make them easier to board for people using wheelchairs or carrying strollers and bikes.

This is smart planning for Philadelphia's six trolley lines that can have effects well beyond making SEPTA more convenient for riders. It can spur economic development in the neighborhoods that use the trolleys as well as make jobs and cultural amenities in Center City and University City more accessible to more people. For evidence, consider that recent growth in Philadelphia has been concentrated in neighborhoods along the Broad Street and Market-Frankford subway lines.

The fervor around the trolley plan picked up last week when the Delaware Valley Regional Planning Commission released its report which offered a first time glimpse at the future. It is one in which trolleys break down less frequently, carry more passengers, and where they are closer to the ground, making it easier for travelers to get on and off.

There would also be fewer stops but that's not as inconvenient as it sounds. They'd be paced about one-quarter of a mile (or roughly five blocks) apart.

There is, however, a big hitch to the overall plan. Improving trolley infrastructure and replacing the cars, a few of which date back to 1948,  would cost $1 billion. SEPTA's plans on funding are still developing, and these improvement projects are typically funded by the Federal Railway Administration. While the Trump administration has been hostile to mass transit funding, Congress has, so far, found a way to maintain support. Future federal funding, however, is likely to require more state and local matching  funds than it does now. The transit agency is supported by local, state and federal funds as well as users who pay fares

State funding is always a gamble in Pennsylvania where the Republican-controlled legislature tends to fall back on tired old ideas, like truck-stop casinos and more sin taxes, than be focused on the complex needs of the future. Although the state adequately funds mass transit now, there isn't unanimity in Harrisburg. As budget talks lingered into September, Republicans proposed slashing funds to SEPTA by about 40 percent. They didn't get their way, but the fact that they considered it, shows their ability to ignore the broad economic value of mass transit.

That makes it even more important that transit activists already are quietly discussing more local funding for the regional agency with the five counties it serves. Those counties are all benefiting from recent transit improvements and growth in this region, especially from Philadelphia, which has grown in each of the last 10 years, according to the latest Census figures. Commuters and businesses would be wise to start asking their state representatives to maintain funding and tell their county leaders that transit matters to all of us.