PennDOT considered an alternative that involved the replacement of the existing raised concrete traffic islands with full width paved shoulders and concrete median barrier separating mainline SR 0001 traffic from service road traffic. The alternative would eliminate the intermediate crossovers requiring entrance and exit at the northern and southern endpoints of the service roads and would replace the existing West Interchange Road overpass.

This alternative was presented at a public officials’ meeting, open house public plans display, and town hall meeting in May and September 2014. The public raised concerns involving increased traffic volumes along the service roads, increased emergency services response times to incidents along mainline SR 0001, and lack of noise mitigation.

• A traffic study was completed at the time this alternative was being developed. The results of that study determined there would be an increase in traffic volumes along the service roads (the southbound service road ranges from an 18.0% increase to a 625.0% increase with northbound ranging from 28.0% to 760.0% between 2050 no build and 2050 build conditions). It was determined this alternative would meet the need of improving current design standards; however, it would not meet the needs of safety or improving system continuity and driver expectations. 
  2050 No Build Frontage Road Volumes
  2050 Build Frontage Road Without Crossovers Volumes 
• Improving system continuity and driver expectations. This alternative would not improve system continuity due to the continued indirect manner in which the traffic would need to travel to access between SR 0001 and PA 413, or access between SR 0001 and Old Lincoln Highway and Highland Avenue.  Additionally, this alternative would not improve driver expectations because the expectation for SR 0001 in this area would be to have interchanges providing access between major crossing arterials. 
• Existing roadway configurations and traffic conditions contribute to safety concerns in the project area. The alternative does not meet the safety need because the post construction design is very similar to the existing although it does remove the potential crash clusters at the intermediate crossovers. Additionally, per the local EMS feedback, the alternative would potentially excessively increase EMS response times because they would not be able to access SR 0001 by crossing over the concrete islands since there would be proposed concrete median barrier separating the service roads from SR 0001.

For those reasons, coupled with the public’s concerns, this alternative was dismissed from further study.

The detailed traffic analysis can be found in the U.S. 1 Frontage Road Traffic Assessment Technical Memorandum, dated July 2012, located in the project technical file.

The current design for PA 413 (Pine Street) includes both a sidewalk along the southbound side and a sidepath along the northbound side to facilitate both bicycle and pedestrian traffic along Pine Street. Additionally, crosswalks and pedestrian signal phases are proposed at both interchange ramp intersections to safely facilitate bicycle and pedestrian crossings.

The local municipality is responsible for the maintenance of the existing service roads. In the future build condition, the local municipality will be responsible for the remaining portions of the service roads with certain exceptions.

This traffic will access US 1 using the interchange at PA 413 (Pine Street) or the access points at Old Lincoln Highway and Highland Ave.

Based on Streetlight data collected by the design team and verified by Inrix data collected by PennDOT for the existing conditions, when traffic leaves U.S. 1 southbound via the southbound service road and exits onto Bellevue Avenue, 49.0% in the AM peak hour and 60.4% in the PM peak hour are traveling toward Newtown with the second highest portion of traffic being residential traffic living in the adjacent neighborhoods.

When traffic leaves U.S. 1 northbound via the northbound service road and exits onto Bellevue Avenue, 42.8% in the AM peak hour is traveling to the adjacent neighborhoods and 43.6% of traffic in the PM peak hour is traveling south onto Pine Street toward Business Route 1. The second largest portions of the traffic in the AM peak hour are split traveling north or south on PA 413 and the second largest portions of the traffic in the PM peak hour are split between the adjacent neighborhoods and heading north on PA 413 toward Newtown. The following graphics depict the breakdown for all traffic exiting U.S. 1 via Bellevue Avenue. Origin-Destination Data

All of this data was coupled with PennDOT’s actual traffic counts to better understand current traffic patterns and calibrate the proposed traffic model.

PennDOT understands the concern with safety on the local roadway network. The Department has incorporated traffic calming within the current project limits and will continue working with local officials to identify additional reasonable traffic calming accommodations, where feasible.

After thorough review of the archaeological report’s documentation, as well as review of maps and aerial photographs demonstrating the evolution of the cultural landscape on the cemetery block, no evidence was found that the Revolutionary War cemetery extends into the proposed RC3 project footprint. The portion of the proposed project footprint in the vicinity of the cemetery underwent an archaeological resources identification survey, and no evidence of the cemetery was encountered.

The RC3 project design team is aware of the sensitivity of the cemetery and its vicinity. They will notify the PennDOT District 6-0 cultural resources professionals if the proposed design were to change and cause an impact to any areas that were not previously investigated. If there is a change that expands the design plans outside of previously investigated areas, PennDOT will complete additional surveys.

The ground disturbance footprint of where PennDOT proposes to construct two U.S. 1 ramps and widen PA 413 (Pine Street) has undergone an archaeological resources identification survey. No Indigenous archaeological sites were encountered.

The RC3 project design team will notify the PennDOT District 6-0 cultural resources professionals if the proposed design were to change and cause an impact to any areas that were not previously investigated. If there is a change that expands the design plans outside of previously investigated areas, PennDOT will complete additional surveys.

PA 413 (Pine Street) is federally classified as a Regional Principal Arterial. This classification of roadway is meant to carry most trips entering and leaving the area and serves intra-area travel. In the existing condition, U.S. 1 traffic must exit the mainline via frontage roads and then disperse onto neighborhood streets, and then travelers work their way to a major street (e.g., Pine Street) to continue or complete their trips. Providing a direct connection to PA 413 (Pine Street) via an interchange reduces traffic on neighborhood streets and places vehicles directly onto PA 413 (Pine Street) via a modern interchange design.

The current roadway layout does essentially function as an informal interchange in the existing condition. Currently, southbound U.S.1 traffic exits onto the southbound service road, then turns right onto Bellevue Avenue. and either stays straight up to PA 213 (Maple Avenue) or it turns right onto Gillam Avenue to access PA 413 (Pine Street). Likewise, northbound U.S. 1 traffic exits onto the northbound service road, then turns right onto Bellevue Avenue to access PA 413 (Pine Street). Bellevue Avenue is a state route but is only classified as a Minor Arterial and is primarily a residential neighborhood street within the immediate vicinity.

Through the project development process, three final build alternatives were selected by the project team for further study. The three alternatives were Alternative 1 (Frontage Road Access Modifications), Alternative 2A (ParClo), and Alternative 2B (DDI). These alternatives included the original preferred alternative for the project and two interchange alternatives. A summary comparison of the three build alternatives is as follows and shown in the Alternatives Comparison Table.

Alternative 1 has the lowest estimated construction cost and is least impactful in terms of anticipated right-of-way, utility, environmental, and structural impacts. However, this alternative was previously dismissed due to not fully and effectively addressing the project purpose and need, as well as public concerns involving increased traffic volumes along the service roads, increased emergency services response times to incidents along mainline SR 0001, and lack of noise mitigation.

When comparing the two interchange alternatives from a traffic operations perspective, both the ParCLO and DDI interchange signalized intersections are expected to operate acceptably in the 2050 design year with all interchange intersections expected to operate at LOS C or better in the ParCLO in both peak hours and LOS B or better in the DDI in both peak hours. The DDI is expected to operate better than the ParCLO at the interchange intersections, which is expected due to the need for only two phases at each of the signalized intersections that is inherent in the DDI design. At other study area intersections adjacent to the interchanges, the ParCLO and DDI alternatives are expected to have similar operations with queues and delay expected to increase at adjacent intersections due to added volume on SR 0413 in both alternatives. However, queues on SR 0413 in the DDI alternative are expected to be longer and potentially impact the SR 0001 southbound off-ramp. In terms of predicted safety performance on the freeway segments, the two alternatives are predicted to be similar. The DDI interchange intersections are predicted to have a slightly lower crash frequency than the other alternatives.

The DDI is expected to be more impactful in terms of right-of-way, structural and access impacts and construction cost. The DDI will impact all four quadrants of the proposed interchange area, requiring more right-of-way, whereas the ParCLO will only have significant impacts to two quadrants. When compared with the ParCLO, the DDI will require either two additional structures or one additional structure and an additional span on the PA 413 (Pine Street) structure over SR 0001 for the proposed SR 0001 Southbound on- and off-ramps to Gillam Avenue. The DDI also removes direct access between PA 413 (Pine Street) and Gillam Avenue and restricts access to Woods Drive to right-in / right-out only on PA 413 (Pine Street). The ParCLO maintains full access between PA 413 (Pine Street) and Gillam Avenue and Woods Drive while also providing a full access interchange between PA 413 (Pine Street) and SR 0001.

Alternative 2A ParCLO was identified as the preferred interchange option for this project area due to addressing the project purpose and need and being less impactful in terms of right-of-way, access, structures and construction cost compared to Alternative 2B DDI.