Flourtown. Jenkintown. Ardmore. What do all these places have in common?
They're all four-lane Main Streets in rights-of-way really too narrow to handle them. Too much of the right-of-way is dedicated to making through traffic move fast; too little to ensuring good pedestrian movement. Each of these Main Streets is a historic Main Street with average or above-average place intensity; in each, there is no good reason to sacrifice parking and sidewalk for traffic lanes.
Let's start with Flourtown. Built as a linear village sprawling along Bethlehem Pike, it stretches (and has stretched for at least 150 years) through Springfield Township--its primarily population concentration--from Chestnut Hill to Whitemarsh. It is subdivided into three sections: Erdenheim and Valley Green bookend Flourtown proper.
Now, tell me why on earth is this stretch of Bethlehem Pike four lanes? Certainly, it used to be the south end of the main trade route from Philadelphia to the Lehigh Valley--which is why Flourtown grew in the first place--but that function has since been bypassed by the Fort Washington Expressway, which connects rather into Cheltenham and Ogontz some miles off. A suburban extension of Chestnut Hill, Bethlehem Pike in Flourtown functions as a natural Main Street, albeit one cut in several places by strip malls, and never gets the kind of traffic four lanes should demand. Indeed, in a spontaneous experiment, Aqua has been repairing water pipes under the street, which has halved effective capacity, without inducing onerous traffic conditions.
Its through-road capabilities diminished, it is apparent this stretch of Bethlehem Pike needs instead to capitalize on placemaking to help further develop Flourtown. This can be done by simply getting rid of the two extraneous lanes, narrowing them to parking lanes, and in the four-feet-a-side of added space run either (a) a bike lane, or (better) (b) expand the sidewalk.
If Flourtown was easy, Jenkintown is harder. PA-611 runs along its Main Street, Old York Road, which (due to the region's underbuilt highway system) is the main artery from Philadelphia to points north. Old York Road links Broad Street with Easton Road, the long-distance pike, and is as such still very much a key trade route.
But it is not an insurmountable problem. Like Ambler, Jenkintown is enough a place to hold its own without through traffic--traffic that usually stops not on Main Street, but rather in strip malls beyond (in this case, primarily Willow Grove to Noble). And Easton Road is reasonably straight and meets the city at Cheltenham-Ogontz, allowing 611 traffic use of (very) wide Cheltenham Ave. to Broad St.
...Unfortunately, this passes through downtown Glenside and Roslyn. If the point is to bypass downtown, what use is it to simply bypass one downtown for another? A better route between the two would be Rices Mill Road-Highland Avenue, which would thread between Wyncote and Glenside.
The hardest is dealing with Lancaster Pike, Ardmore's Main Street, in a situation like 611, but with more downtowns still--this would also involve a bypass of Bryn Mawr.
The reason this is more difficult is because of the nature of the Main Line, and because no useful bypass exists for Wayne or Paoli further up. Regardless, a feasible bypass begins at Villanova, and follows Spring Mill Rd. to Montgomery Ave. This route follows Old Lancaster Pike to 54th St., a better one would follow Wynnewood Ave./Rd. back to Lancaster Pike by Lankenau, sucessfully bypassing the heart of the Main Line but leaving the through route intact.
All of these solutions are inexpensive. I am not talking about building new freeways here; rather, I am simply talking about re-signing numbered highways along different routes to allow strong Main Streets better placemaking. Keep in mind that Ardmore, in particular, is a major transit village and a development model for much of the Philadelphia metro.