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This 2005 photo shows the northbound Mid-County Expressway (I-476) at EXIT 16 (I-76 / Schuylkill Expressway) in Conshohocken. (Photo by Steve Anderson.)


20.3 miles (32.7 kilometers)

"I remember going to the state highway office, which was in a bank building at Ardmore, and they said, 'Sure, sounds great. Have you got the unanimous consent of all the communities this road is going to go through?' We said, 'Yeah, we've got them all except Swarthmore.' They said, 'Well, do that, and we'll put it on the map.' " - Henry D. Harral, recalling a 1951 meeting as Delaware County planning director in a 1985 Philadelphia Inquirer interview

UPDATING AN OLD CORRIDOR: In 1929, regional officials in Philadelphia's western suburbs proposed a circumferential highway that was to connect the Valley Forge area with the industrial seaport of Chester. The highway would not only allow traffic to bypass the city of Philadelphia, but also take traffic off less direct local roads such as PA 252, PA 320 and PA 420. These narrow roads were laid as early as the 1680's by some of Pennsylvania's earliest settlers, who placed them midway between the creeks that flowed south to the Delaware River for the convenience of farmers who settled along the streams.

THE DARBY CREEK-COBBS CREEK PARKWAY: In 1932, the Regional Planning Federation (the predecessor agency to the Delaware Valley Regional Planning Commission) proposed a parkway system around the Philadelphia area similar to that constructed by Robert Moses. Like the Moses parkways in New York, the four-lane parkways were to feature controlled access, stone-arch bridges, timber lightposts and natural vegetation.

The regional plan featured a proposed scenic parkway along the Darby Creek and Cobbs Creek valleys. However, without a forceful "power broker" such as Moses to direct public works projects in the Delaware Valley, the route remained a dotted line through Delaware and Montgomery counties for decades to come.

TOLL ROAD PLANS FOR THE POSTWAR ERA: As traffic volumes increased after World War II, transportation officials revived the circumferential highway proposal. In addition to providing improved access through Philadelphia's western suburbs, the expressway was hailed as a potential savior for the city of Chester, which had experienced widespread poverty following the collapse of the shipbuilding industry after World War II. The expressway would provide the necessary truck link between Philadelphia International Airport and proposed seaport facilities in Chester to the south, and the Pennsylvania Turnpike to the north.

With state and Federal funds difficult to obtain in the immediate postwar era, the Pennsylvania Turnpike Commission (PTC) took over planning for the route, and the route as part of the "Chester Extension" of the Pennsylvania Turnpike. Along with the "Delaware River Extension" (which was constructed in the mid-1950s and serves as today's I-276), the "Chester Extension" was to provide a true bypass of Philadelphia. These two routes were to connect to a "Northeast Extension" at Plymouth Meeting, Montgomery County. These three routes were part of the PTC's 750-mile toll network, as proposed in 1954.

The routes shown on this map are from a 1958 location report for the Mid-County Expressway. Only the main colored routes -- the easterly (red-yellow) route, the central (blue) route and the western (green) route -- are shown. The "blue route" promised the most potential traffic service while offering the least potential community disruption. Nevertheless, the route encountered stubborn opposition because of its location through the environmental sensitive Darby Creek and Crum Creek valleys.

(Map from "Interstate 476, Mid-County Expressway from I-76 to I-95: Administrative Action Draft Environmental Impact Statement and Section 4(f) Statement," Federal Highway Administration and Pennsylvania Department of Transportation (1976); supplied by Sandor Gulyas.)

MARKED BY A BLUE LINE: In 1955, the Federal Bureau of Public Roads (BPR) added the Mid-County Expressway - as the route came to be officially called - to the preliminary Interstate highway network, and one year later, when President Eisenhower signed the Federal highway aid act into law, the expressway became eligible for 90 percent Federal financing. (State and local governments were to pay the remaining ten percent of the costs.) State officials originally proposed an I-495 designation for the route in June 1958, but the American Association of State Highway Officials (AASHO) assigned an I-480 designation for the route in November 1958.

During this period, planners from the Pennsylvania Department of Highways mapped out the following three alternative north-south routes for the expressway:

  • RED (YELLOW) ROUTE: The first route was an easterly alignment that cut through the western edge of Springfield Township. Since it went through more urbanized areas, right-of-way and construction costs would have been prohibitive.

  • GREEN ROUTE: The second route was a westerly alignment that coursed west of Media. Although right-of-way and construction costs would have been lower than the other alternatives, the alignment provided the least service and traffic relief.

  • BLUE ROUTE: The third route was a central alignment that paralleled the PA 320 corridor. This alignment, which went along the Darby Creek and Crum Creek valleys, provided the most traffic relief and least community disruption along the three alternatives.

The $40 million "Blue Route" originally was scheduled for completion by 1964. However, there was still no "Blue Route," except on planning maps.

LEFT: Looking southbound along the "Blue Route" in Conshohocken, Montgomery County in 1974. The overpass in this photo carries Old Gulph Road over the incomplete section of I-476 south of I-76, which would not open until 1991. RIGHT: The completed EXIT 16 (the I-476 / I-76 interchange) in Conshohocken, Montgomery County in 1978. One year after this photo was taken, the I-476 section north of I-76 opened to traffic. (Photos by Scott Kozel.)

SEEKING APPROVAL FROM OFFICIALS AND COMMUNITIES: In December 1961, the first of what would become more than two decades of contentious public hearings took place. Although the proposed "Blue Route" was to take fewer homes than the other alignments, nearby residents feared that the highway would spoil the Darby Creek and Crum Creek valleys. One group, Citizens for a Crum-Ithan-Darby Trail, lobbied President Lyndon Johnson to convert the "Blue Route" corridor into a linear trail park, and staged walks along the route to prevent its construction.

Behind the scenes, the fighting involved powerful political and business leaders. At Swarthmore College, officials feared that the highway would spoil the pastoral atmosphere of the campus. Two Swarthmore alumni, nationally syndicated columnist Drew Pearson and Scott Paper Company president Thomas B. McCabe maneuvered to have the highway bypass their alma mater. Further south, prominent Chester lawyer J. H. Ward Hinkson fought a proposed pathway that would slash through his beautifully landscaped backyard.

These community concerns were incorporated into the final design process, which began in 1964. That year, the Mid-County Expressway, which was re-designated I-476 (from the original AASHO I-480 designation), was estimated to cost $78 million. One year later, the BPR officially approved the modified "Blue Route," and the Pennsylvania Department of Highways added I-476 to the six-year capital improvement program. Right-of-way acquisition commenced shortly thereafter.

In 1970, the newly organized Pennsylvania Department of Transportation (PennDOT) completed a 2.5-mile-long section of the "Blue Route" through Broomall and Bryn Mawr, and four years later, completed a 1.5-mile-long section through Radnor. However, the two unopened sections of six-lane highway did not connect to other highways or local streets. For nearly two decades, no traffic - save for the occasional highway engineer, bicyclist or drag racer - had used the highway. One section had even been used as a parking lot for a nearby golf tournament.

PennDOT also purchased land on the west side of the I-476 right-of-way in Radnor for a proposed transportation center and park-and-ride facility. Located just north of the current EXIT 13 (US 30), the transportation center was to serve SEPTA's Route 100 high-speed line and a relocated Radnor commuter rail station on the R5 line. Budget constraints ultimately led to the cancellation of this plan, but a vestige of this plan at the Amtrak/SEPTA (R5) underpass, where an unused right-of-way along the southbound lanes of I-476 was to have been used for a ramp to the park-and-ride lot.

This guide, "Reducing Impacts Through Improved Highway Section Design," was used for the four-lane "parkway" section of I-476 through Delaware County. The typical condition selected was at Sussex Boulevard and Lawrence Park in Broomall.

  1. Original six-lane design (60-foot median): The wide median and inflexible geometry of the original expressway design would have resulted in much excavation and grading, extensive relocation and re-channelization of streams, and severe impacts on the stream valley environment.

  1. Task force four-lane design (36-foot median): With reduced median width and design speeds (70 MPH to 60 MPH), a more flexible geometry was possible with the "task force alternative," reducing creek relocations and avoiding sensitive areas, while maintaining the same protection to adjacent residences.

  1. Refined task force four-lane design (36-foot median): Increased emphasis on design flexibility and sensitivity, such as selective use of steeped lanes to meet difficult sidehill conditions in the corridor, will further reduce impacts, both in the stream valleys and alongside the corridor. Where possible, the use of low walls to support earthen beams can provide improved noise abatement with fewer visual impacts than noise walls.

Diagram from "Overview of Departmental Recommendations on the Blue Route (I-476)," Pennsylvania Department of Transportation (1984).

ENTER THE ENVIRONMENTALISTS: With new Federal and state environmental regulations coming to fruition in the early 1970s, opponents had new ammunition to fight the "Blue Route." Between 1970 and 1972, early environmental impact statements studied the highway's potential impacts on Darby Creek and Crum Creek. The Federal Highway Administration (FHWA, which superceded the BPR) and the Pennsylvania Department of Transportation (PennDOT, which superceded the Pennsylvania Department of Highways) approved these studies.

Nationwide, the early 1970s marked a period of large-scale changes in highway planning. In 1973, environmental laws became retroactively applicable to previously approved Federal highway projects, and consequently, the early I-476 studies were made null and void. Strong cognizance of this national trend by local groups caused I-476 to become one of the first projects to be reassessed. By 1974, the entire 21.5-mile length of I-476, from I-95 (Delaware Expressway) in Chester north to I-276 (Pennsylvania Turnpike-Delaware River Extension) in Plymouth Meeting was subject to a larger-scale environmental impact study. (However, construction continued on the I-476 interchanges at I-76 and I-95, since these projects were already under contract.)

Between 1976 and 1978, PennDOT held public hearings for the draft and final environmental impact statements along the proposed I-476. The proposed route, which was to be six lanes along its entire length, differed from the current configuration in that it was to feature cloverleaf interchanges at US 1 (Media Bypass), PA 3 (Baltimore Pike) and US 30 (Lancaster Avenue), and a partial diamond interchange at PA 320 (Sproul Road). (PennDOT dropped plans for interchanges with the Lansdowne Expressway and the US 422 Expressway-Radnor Spur when those highways were canceled in 1977.)

The environmental statements said that I-476 would alleviate congestion on parallel north-south roads, contribute to greater fuel efficiency (with the reduction of stop-and-go driving), provide improved accessibility to commercial and industrial centers, and spur the creation of approximately 2,500 jobs. In addition, the statements touted the following benefits:

  • Motorists using the road would be provided an attractive view, made up of residential neighborhoods separated by open space in the form of rolling hills and stream valleys with considerable woodland.

  • The amount of excavation needed for the highway would provide cover for the existing landfills in Delaware and Montgomery counties.

  • The highway would preserve the usability of the parks over which it passes, and in some cases (where the highway was to cross over parkland) make them all-weather facilities.

However, critics accused PennDOT of awarding the preparation of the environmental impact statements to the same firm that designed the already constructed section of I-476 without bidding.

The "Blue Route" crosses several major rail lines. LEFT: This 1999 photo shows the trestle for the SEPTA R3-Media rail line near Springfield Township. (Photo by Steve Anderson.) RIGHT: This 2003 photo shows the trestle for the SEPTA R5-Main Line and Amtrak tracks in Radnor Township. Unused right-of-way along the southbound lanes at this underpass hint at canceled plans for an interchange leading to a proposed transportation center and park-and-ride facility. (Photo by Jim K. Georges.)

THE FIRST BLUE ROUTE SECTION OPENS: Meanwhile, construction continued on a three-mile-long section of the "Blue Route" between EXIT 16 (I-76 / Schuylkill Expressway) in Conshohocken and EXIT 19 (Germantown Pike) in Plymouth Meeting. This section of I-476 in Montgomery County, which included a high fixed-level bridge across the Schuylkill River, opened in 1979.

MORE OBSTACLES: In March 1979, the FHWA advised PennDOT that it would not accept the final environmental impact statements on the incomplete sections unless the following engineering, financial and legal issues were addressed:

  • down-scoping of the entire project, including number of lanes and interchanges
  • financial capabilities of PennDOT
  • mass transit interfaces with adjacent SEPTA lines

Responding to the FHWA challenge, PennDOT convened a task force to address these issues in August 1979. PennDOT submitted the results of this task force with a revised environmental statement in May 1980, and three months later, the FHWA approved the I-476 plans. However, these plans were thwarted once again in November 1981, when the Delaware County townships of Marple, Radnor, Ashwood Manor, and Swarthmore, along with the Citizens County of Delaware County, were successful in their attempts in U.S. District Court to stop construction.

By the mid-1980s, young people had grown to middle age raging against or advocating the highway. The road had dissolved into rumor so long before that 18 families in Marple Township had moved into new homes in the path of the highway. It appeared that the "Blue Route" never would be completed.

This 2003 photo shows the southbound Mid-County Expressway / "Blue Route" approaching EXIT 13 (US 30 / Lancaster Avenue) in Radnor Township. (Photo by Jim K. Georges.)

GETTING BACK ON TRACK: In 1983, two new environmental impact statements were drafted for the missing links of I-476. The proposed highway was designed for 50,000 vehicles per day (AADT) along the four-lane section south of PA 3, and 70,000 vehicles per day along the six-lane section north of PA 3. Both sections featured 12-foot-wide lanes, 10-foot-wide shoulders, variable medians and a 65 MPH design speed. The two EIS documents were summarized as follows:

  • From I-95 north to I-76, the new EIS for the "Blue Route" featured a downsized, four-lane "parkway"-like route from McDade Boulevard north to PA 3, and a six-lane route that used previously built sections between PA 3 and I-76. This plan, which had a 69 percent reduction in stream relocation and a 14 percent reduction in right-of-way acquisition, required fewer takings of residences, parkland and historic sites. The interchanges at EXIT 5 (US 1), EXIT 9 (PA 3) and EXIT 13 (US 30) were downsized, and the interchange for EXIT 6 (PA 320) was eliminated. In an innovative use of mitigation techniques, PennDOT erected concrete sound barriers in which pockets allow vines, shrubs, or ground cover to take root. Earthen berms and natural vegetation were also used to shield surrounding communities from the effects of the highway. Finally, lightposts and guardrails were blended into the landscape.

  • From Ridge Pike north to I-276, the new EIS featured not only a six-lane extension, but also a complex interchange between the Mid-County Expressway, and the Delaware River and Northeast extensions of the Pennsylvania Turnpike. The interchange comprised a massive 17-lane toll plaza, seven bridges and 4.4 miles of ramps linking I-476 to the turnpike facilities.

To minimize noise along the I-476 corridor, maximum grades were reduced from 3.8 percent to 2.8 percent. This grade reduction meant that heavy trucks would cause less community disruption when ascending hills. The installation of a seamless asphalt pavement - a deviation from the standard PennDOT practice of putting in jointed concrete pavement sections - was to produce further decreases in noise pollution.

The "Blue Route" plans in both EIS documents were compatible with updated land use plans in Delaware and Montgomery counties. They also included park-and-ride facilities for four intersecting commuter rail lines - a user-friendly feature that did not appear in the original plans from the 1950s. PennDOT secretary Thomas D. Larson called the revised plans for I-476 "a national showcase of design excellence" and "an environmental resource."

One year later, the case for completing I-476 became more substantiated when a report by the Delaware Valley Regional Planning Commission (DVRPC) underscored the need for an encircling highway network. The study found that many more suburbanites commute to jobs elsewhere in the suburbs than to jobs in Philadelphia.

Opposition to the highway kept all or part of it tied up in legal battles until 1985, when a Federal judge gave the green light to construction of I-476, provided it included extensive environmental safeguards. The next year, the U.S. Supreme Court refused to hear arguments in the case.

Two views of the construction of EXIT 20 (the I-476 / I-276 interchange) in Plymouth Meeting. The northernmost section of the "Blue Route" was completed in December 1992, one year after an important 16.5-mile-long section from I-76 south to I-95 opened to traffic, and 13 years after the initial section north of I-76 opened to traffic. (Photos by Pennsylvania Turnpike Commission via Jeff Kitsko.)

COMPLETING THE MISSING LINKS: In 1985, PennDOT resumed construction of the "Blue Route." Two years later, a $28 million segment of interchanges connecting I-95 and McDade Boulevard near the southern terminus in Chester opened to traffic. At that time, the signs on I-95 only pointed motorists toward McDade Boulevard; there were no references to I-476.

On December 19, 1991, the most contentious section of I-476, between EXIT 1 (McDade Boulevard) and EXIT 16 (I-76 / Schuylkill Expressway), was opened to traffic by a host of dignitaries. Finally, on December 16, 1992, more than six decades of planning, controversy and construction had come to an end with the completion of the Plymouth Meeting extension and interchange. One of the last Interstate highways to be completed nationwide, I-476 was constructed at a cost of $600 million, or fifteen times the original 1957 estimate. Nearly 375 families were displaced for construction of the Mid-County Expressway.

HAS THE BLUE ROUTE BECOME A VICTIM OF ITS OWN SUCCESS? Only a decade after the "Blue Route" opened, traffic volumes projected for 2010 already had been surpassed. To alleviate congestion, officials in Delaware County pressed PennDOT and the FHWA to begin hearings on widening the four-lane section to six lanes. PennDOT and FHWA both rejected the proposal, stating that the four-lane section was part of the compromise solution to get I-476 built.

PennDOT has completed and scheduled the following projects to alleviate congestion and improve operating conditions on I-476:

  • PennDOT completed installation of meter lights along entrance ramps to I-476 during the late 1990's. The meter lights were operational for two years, but had to be shut down in 2001 because they could not be controlled remotely. Following a systems upgrade, the meter lights became operational again in November 2004. The upgraded meter lights work in conjunction with a $9 million variable message system installed by PennDOT.

  • During 2001, PennDOT replaced the sequentially numbered exit tabs with new mileage-based exit tabs. The new mileage-based exit numbering system on I-476 complies with the preferred FHWA exit numbering system used in many states, and now is used statewide.

  • In 2005, PennDOT and the Pennsylvania Turnpike Commission (PTC) completed construction of four high-speed (55 MPH) EZ-Pass lanes - two in each direction - connecting the "Blue Route" (I-476) with the Pennsylvania Turnpike (I-276) and the Northeast Extension (I-476).

  • PennDOT repaved the 16-mile-long section of I-476 from the I-95 junction north to EXIT 16 (I-76 / Schuylkill Expressway). Opened in 1991, this section had been subject to heavier-than-projected traffic conditions and therefore needs rehabilitation. Both the I-476 mainline and ramps were repaved, and several bridges were repaired. In addition, short sections of I-95 and I-76 were repaired where they intersect I-476. The $17 million first phase of the project from I-95 north to EXIT 9 (PA 3 / Baltimore Pike) was finished in mid-2006, while the second phase of the project from EXIT 9 north to EXIT 16 was completed in mid-2007.

  • PennDOT is rebuilding 3.5 miles of I-476 from EXIT 16 north to the Pennsylvania Turnpike junction in Plymouth Meeting. In addition to rebuilding the roadway, which was originally built in the late 1970s, PennDOT is widening the left and right shoulders, upgrade acceleration-deceleration lanes, and replace drainage. The project also includes reconstruction of the I-476 bridge over the Schuylkill River. Construction of the $72 million began in 2008, with completion scheduled for late 2011.

According to the DVRPC, I-476 carries now approximately 90,000 vehicles per day (AADT) along its southern half, and approximately 130,000 vehicles per day along its northern half.

This 2003 photo shows the northbound Mid-County Expressway / "Blue Route" at EXIT 19 (Germantown Pike) in Plymouth Meeting. (Photo by Jim K. Georges.)

EXPAND THE SOUTHERN END TO SIX LANES: The "Blue Route" should be expanded from four to six lanes between EXIT 1 (MacDade Boulevard) and EXIT 9 (PA 3 / Baltimore Pike). Rush-hour HOV lanes also should be considered for the left lanes. To preserve the character of the area, the parkway-like characteristics of I-476 should be maintained even as the highway is expanded.

SOURCES: Regional Plan of the Philadelphia Tri-State District, Regional Planning Federation (1932); "Pennsylvania Turnpike System," Pennsylvania Turnpike Commission (1951); "Loop Highways To Cut Tie-Ups Urged for Area" by James P. McFadden, The Philadelphia Inquirer (12/22/1957); Pennsylvania: Keystone of the Interstate Highway System, Chamber of Commerce of Greater Philadelphia (1958); "Philadelphia Road Stirs Controversy," The New York Times (6/21/1964); "Crum-Ithan-Darby Trail in Delaware County, Pennsylvania," Citizens for a Crum-Ithan-Darby Trail (1965); "Philadelphia's Comprehensive Plan for Expressways," Philadelphia City Planning Commission (1966); "Six-Year Improvement Program (1967-1973)," Pennsylvania Department of Highways (1967); 1985 Regional Transportation Plan, Delaware Valley Regional Planning Commission (1969); "Blue Route: $172 Million Road to Nowhere," The Philadelphia Inquirer (5/23/1976); "Interstate 476, Mid-County Expressway from I-76 to I-95: Administrative Action Final Environmental Impact Statement and Section 4(f) Statement," Federal Highway Administration and Pennsylvania Department of Transportation (1983); "Interstate 476, Mid-County Expressway from Ridge Pike to I-276: Administrative Action Final Environmental Impact Statement and Section 4(f) Statement," Federal Highway Administration and Pennsylvania Department of Transportation (1983); "Schuylkill Carries the Load of Many Roads Left Unbuilt" by Paul Nussbaum, The Philadelphia Inquirer (8/19/1984); "Overview of Departmental Recommendations on the Blue Route (I-476)," Pennsylvania Department of Transportation (1984); "A 56-Year-Old Idea, Blue Route Creeps Toward Reality," The Philadelphia Inquirer (12/09/1985); "How the Blue Route Will Color the Region's Future," The Philadelphia Inquirer (12/15/1991); "Why It's Called the Blue Route," The Philadelphia Inquirer (12/15/1991); "The Blue Route's Debut" by Marie McCullogh, The Philadelphia Inquirer (12/20/1991); "A Red-Ribbon Day Opens the Blue Route All the Way," The Philadelphia Inquirer (12/17/1992); "Blue Route's Popularity Drives Volume Predictions Off Map," The Philadelphia Inquirer (8/24/1993); "Blue Route Proposal Stirs Up New Foes," The Philadelphia Inquirer (11/05/1994); "Noisy Highways" by Philip Langdon, The Atlantic Monthly (August 1997); "Lights Signal New Era for Blue Route Commuters," The Philadelphia Inquirer (10/27/1999); "Professors Write Book Following Blue Route's Long and Winding Path" by Mark Stroh, The Philadelphia Inquirer (7/21/2000); "Firms Take on Traffic Woes" by Natalie Kostelni, Philadelphia Business Journal (11/03/2000); "Repairs Scheduled for I-476 and I-95," WPVI-TV (10/21/2004); "Meters Will Stagger Rate Cars Enter Route 476," WCAU-TV (11/15/2004); "Brake Lights Soon on Blue Route" by Jere Downs, The Philadelphia Inquirer (5/11/2005);  "Local EZ-Pass Express Lanes To Open," WPVI-TV (10/11/2005); "Construction Comes to Blue Route" by Erin O'Hearn, WPVI-TV (3/12/2009); "I-476 / Blue Route Improvement Project," Pennsylvania Department of Transportation (2009); Asphalt Pavement Alliance; Mike Garvin; Sandor Gulyas; Jeff Kitsko; Scott Kozel; Alex Nitzman; Anthony Panichelli; Len Pundt; Sandy Smith; Stephen Summers; William F. Yurasko.

  • I-476 shield by Ralph Herman.
  • Lightposts by Millerbernd Manufacturing Company.
  • HOV lane sign by C.C. Slater.





  • Mid-County Expressway ("Blue Route") exit list by Steve Anderson.

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