APPENDIX B. Excerpts from the October 2002 Conceptual Alternatives Report

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1 APPENDIX B Excerpts from the October 2002

2 Interstate 83 and PA Route 921 The objective for the SR 921 interchange site was to study alternatives for construction of a new interchange. There are no short-term alternatives developed for this site. Four build alternatives and the no-build alternative were studied at this site. These include the following: Alternative A: Partial cloverleaf interchange Alternative B: Trumpet interchange Alternative C: Diamond interchange north of SR 921 crossing Alternative D: Diamond interchange directly at SR 921 crossing Alternative E: No-build Each interchange alternative was evaluated based on how it handled the traffic demands, conformed to current engineering criteria and minimized impacts to resource features including environmental, social and cultural resources. A legend is included in Appendix B detailing the resource features. Regardless of the alternative, the traffic volumes using the proposed SR 921 interchange build alternatives in year 2030 will be the same (approximately 750 vehicles during the evening peak hour). The peak hour traffic demands will be accommodated to varying degrees of success by each of the ramp configurations for each of the four alternatives. The construction of a new interchange at SR 921 will not only provide for improved access to the industrial park / business areas along Willow Springs Road, but it will also increase the likelihood of similar development in the immediate vicinity of the proposed interchange. As such, the proposed interchange will need to be designed to provide for the following: Adequate capacity Adequate queue storage between intersections Ability to accommodate additional traffic from future development of adjacent parcels The following summaries for each interchange alternative address the impacts and concerns associated with each option. Alternative A This interchange alternative utilizes a partial cloverleaf design in the northeast and southwest quadrants (refer to Figure 7). In the northeast quadrant, the two ramps connect directly to SR 921 approximately 1100 ft east of I-83. In the southwest quadrant, the two ramps intersect a relocated Bear Road. Bear Road is reconstructed 300 ft further west to provide room for the ramp connections. The I-83 bridge over SR 921 must be widened to accommodate the additional lanes for the interchange ramps. This creates a concern in providing the minimum vertical clearance between the two roadways. This same bridge may need replaced if SR 921 is widened to three lanes. If improvements are made to SR 921, including grade adjustments and lane additions, the SR 921 structures over Little Conewago Creek and its tributary must be widened. All design criteria are met for this interchange alternative. This interchange site contains many of the resource features collected during the environmental overview. The industrial and commercial areas along the east side of I-83 have minimal to no impact. The commercial area, Orchard Business Park, has a small impact to its eastern parcel. The industrial area in the southeast quadrant has no direct impact. Each of these areas is Orth-Rodgers & Associates, Inc. 1 SR 0083 Section 033 York County October 2002 SR 0083 and SR 0921

3 served well by this interchange because the ramp terminals are within 600 ft of their access roads or property boundaries. However, the agricultural areas are heavily impacted by this interchange design in the northeast and southwest quadrants. The high-tension power line adjacent to SR 921 creates a concern as it crosses I-83 into the southwestern quadrant of the interchange. Preliminary traffic analyses of Alternative A have shown that the interchange design provides for fairly adequate storage space between the I-83 northbound ramps intersection, Willow Springs Road and Bear Road with 600 to 800 feet between the intersections. As traffic continues to increase with nearby development beyond year 2030, queuing storage issues and capacity issues could become a concern. Heavy trucks and other vehicles from the nearby developments along Bear Road and Willow Springs Road that are either coming from or headed to I-83 will need to make a series of turns off and onto SR 921. The heavier volumes of turning vehicles will cause an increase in the amount of conflicting movements at the three intersections thereby augmenting the delay and lengthening the queues at these locations. Alternative B A complete trumpet interchange is utilized for this alternative. The placement of the interchange is north of the existing crossing of SR 921 (refer to Figure 8). The connector road for the interchange intersects SR 921 approximately 1800 ft east of I-83. The I-83 bridge over SR 921 must be widened to accommodate the additional lanes for the interchange ramps. This creates a concern in providing the minimum vertical clearance between the two roadways. A new bridge is required at the connector road crossing of I-83. The I-83 bridge over the Little Conewago Creek will need widened to accommodate the new acceleration and deceleration lanes. All design criteria are met for this interchange alternative. The trumpet interchange configuration minimizes impacts to agricultural and potential archaeological areas, however it has a large impact on a commercial area, the Orchard Business Park. Although the area of the park east of I-83 has a large impact, access to this parcel is maintained. The western portion of the park has a significant impact and no direct access is possible from this interchange concept. The high-tension power line along SR 921 in the east is not impacted with this alternative. By combining the local access to the ramps of the proposed SR 921 interchange at one location, Alternative B should eliminate many of the queuing problems that could arise under Alternative A. However, traffic associated with development along Willow Springs Road, Bear Road and the Orchard Business Park must utilize SR 921 for access to I-83. From a traffic operations standpoint, Alternative B is more efficient than Alternative A because the I-83 ramp access with the local roadway system occurs at a single intersection on SR 921. Additionally, the proposed I-83 ramp intersection on SR 921 was placed to minimize direct conflicts with traffic from Willow Springs Road and Bear Road. Alternative C This interchange alternative uses a diamond interchange placed north of the existing crossing of SR 921 (refer to Figure 9). The connector road for the interchange intersects SR 921 approximately 1800 ft east of I-83. The I-83 bridge over SR 921 must be widened to accommodate the additional lanes for the interchange ramps. This creates a concern in Orth-Rodgers & Associates, Inc. 2 SR 0083 Section 033 York County October 2002 SR 0083 and SR 0921

4 providing the minimum vertical clearance between the two roadways. A new bridge is required at the connector road crossing of I-83. The I-83 bridge over the Little Conewago Creek will need widened to accommodate the new acceleration and deceleration lanes. All design criteria are met for this interchange alternative. The diamond interchange minimizes impacts to all resources in the area. The agricultural area in the southeast quadrant is impacted along with the potential archaeological area in the southern portion of the interchange. This alternative has a moderate impact to the commercial area, Orchard Business Park, on each side of I-83, however direct access is provided from the connector roadway to both parcels. The high-tension power line along SR 921 in the east is not impacted with this alternative. Considering traffic operations and circulation, Alternative C is similar to Alternative B in that the access point between the local roadway (SR 921) and the interchange ramps occurs at a single point (the connector roadway intersection with SR 921). The design for this interchange includes a connector roadway that effectively removes traffic from SR 921 that is associated with the proposed Orchard Business Park and wishes to access I-83. Depending on the size, type, and intensity of development that will occur at the Orchard Business Park, high volumes of heavy truck traffic could cause queuing and congestion problems on the connector roadway between the northbound and southbound I-83 ramp terminals. Alternative D This interchange alternative uses a diamond interchange located directly at the existing crossing of SR 921 (refer to Figure 10). Bear Road is relocated 300 ft west to provide intersection spacing along SR 921 for the ramp terminal. In the southeast quadrant Willow Springs Road has a cul-de-sac and a new roadway is constructed to maintain access to SR 921 and meet intersection spacing criteria. Additional improvement may need to occur along SR 921 to provide appropriate sight distance at the new intersections and widening for left-turn lanes at the ramp intersections. Improvements made to SR 921 will likely require replacement of the I-83 bridge over SR 921 and the SR 921 structures over Little Conewago Creek and its tributary would be widened. All design criteria are met for this interchange alternative. The two agricultural areas for this site are impacted by this interchange alternative. The large potential archaeological site in the southeast quadrant is impacted by the Willow Springs Road extension. There are two potential residential displacements along the I-83 southbound offramp. The high-tension power line adjacent to SR 921 creates a concern as it crosses I-83 into the southwestern quadrant of the interchange. The commercial areas to the north of the interchange have minimal impact from the interchange ramps. Although direct access is not provided, the ramp terminals provide a close access point for the Orchard Business Park. The proposed I-83 diamond interchange for Alternative D coupled with the relocated intersections of Bear Road and Willow Springs Road results in four closely spaced intersections on SR 921. The four intersections are situated within a length of 1200 ft of each other. As traffic volumes increase and additional development occurs along Bear Road, Willow Springs Road, and in the Orchard Business Park, a high volume of turning traffic is expected at the four intersections because vehicles associated with new development will desire to access I-83. The large amount of conflicting turning traffic could cause undue delays and queue storage/blocking problems between the intersections. If the future land development is such that a significant Orth-Rodgers & Associates, Inc. 3 SR 0083 Section 033 York County October 2002 SR 0083 and SR 0921

5 proportion of traffic associated with the new development is heavy trucks, the queuing and congestion problems will likely get worse. Alternative E At this time, the No-build Alternative for this site should be considered. The preliminary year 2030 traffic projections with the build alternatives show the evening peak hour traffic volumes are reduced on certain ramps at the adjacent I-83 interchanges with SR 238 (Exit 24) and SR 295 (Exit 28). However, detailed traffic analyses will determine whether the year 2030 peak hour levels of service are significantly improved at the adjacent interchanges and their intersections with the local roadway network by the presence of an SR 921 interchange. Access to Orchard Business Park in the vicinity of SR 921 and SR 238 via Exit 24 might be sufficient in year If the resulting levels of service from the pending detailed traffic analyses do not show appreciable improvements at the adjacent interchanges, then the No-build Alternative will assuredly be a viable alternative. Recommendations We recommend Alternatives C, D and E for further analysis. Alternative C results in adverse impact to the Orchard Business Park, however direct access is provided to the entire park. Additionally, this alternative minimizes agricultural impacts and disruption to the local roadway network. Alternative D does affect the agricultural areas and requires more relocation to the local roads, however the impact to the business park is drastically reduced with this configuration. Alternative E (No-build) needs studied further to assess the benefits of constructing a new interchange at this site. Each alternative merits further analysis to evaluate the environmental and traffic issues. Alternatives A and B are recommended for dismissal from further studies. Alternative A results in the highest impact to agricultural areas and creates traffic movement concerns at the ramp terminals with the project volumes. Although Alternative B handles all traffic movements efficiently for this interchange site, it requires the most substantial impact to the Orchard Business Park. It is not reasonable to continue studies for Alternative B when Alternative C provides a comparable interchange design with lower commercial impact. Orth-Rodgers & Associates, Inc. 4 SR 0083 Section 033 York County October 2002 SR 0083 and SR 0921

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