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I-16/I-75 Improvement Project Advisory Committee Meeting Summary Centreplex August 3, 2000 4:00-6:00p.m. Advisory Committee Participants: Elaine Bolton, Macon Heritage Foundation Grace Bunner, Native American Council Connie Mac Darnell, Newtown Macon Jim David, Ocmulgee Nat'l Monument Daniel Fischer, Caution Macon Joel Harrell, Norfolk Southern Regina McDuffie, Centreplex Paul Nagle, Chamber of Commerce Anita Ponder, City Council David Stanley, Minister Johnny Wingers, Bibb Co. EMA Sid Cherry, Downtown Council Sandra Bush, Resident Project Team Participants: Joseph Palladi, GDOT Angela Alexander, GDOT Rebecca Gifford, GDOT David Miller, GDOT Genetha Rice-Singleton, GDOT Bob Chaapel, FHWA Brad Hale, MAAI Garrett Sauber, MAAI Glenn Scarborough, MAAI Karla Poshedly, MAAI Todd Hill, MAAI Melissa Moreland-Bourbeau, MAAI Jeff Gardner, Brockington & Assoc. Tim Heilmeier, HNTB Liz Sanford, Sycamore Consulting Denise Watts, Sycamore Consulting Discussion Summary The following people would be joining the group as new members of the Advisory Committee: Ms. Sandra Bush, Macon resident and member of the Pierce / Arkwright Advisory Committee Ms. Elaine Bolton, Macon Heritage (replacement for Ms. Maryel Battin) Ms. Grace Bunner, Native American Council Mr. Richard Enesley, Pleasant Hill resident The primary purpose of the meeting was to review the remaining concept alternatives and identify a preferred alternative, and then discussed the criteria to be used in evaluating the alternatives. This included an explanation of level of service (LOS), highway capacity software (HCS), average daily traffic (ADT), design hourly volume (DHV), and stopping sight distance. The different LOS ratings were explained from A to F. The project goal, which includes a detailed color matrix chart listing each alternate with a rating of excellent, good needs improvement or unacceptable in relation to the projects goals was given to each ACM member. A new concept alternative (alternative #7) was introduced as a hybrid of earlier concepts, incorporating their most desirable features. Before continuing further with a discussion of how each alternative was evaluated, two outstanding issues from previous ACM’s were discussed:
I-75 / Riverside Drive half diamond interchange Due to the close proximity of Riverside Drive to Hardeman Avenue, the proposed ramps from Riverside Drive to I-75 (NB exit ramp and SB entrance ramp) would need to be braided with the ramps from Hardeman Avenue to I-75 (NB entrance ramp and SB exit ramp). Ramps from Riverside Drive connecting directly with the core lanes of I-75 would not have enough distance from the Hardeman Avenue ramps to satisfy AASHTO and MUTCD criteria (i.e. unsafe weaving movements would occur). Engineering diagrams were used to show how the construction of braided (grade separated) ramps would greatly impact the Pleasant Hill District. A traffic engineer with MAAI explained how the traffic had been analyzed at the Hardeman Avenue/Forsyth Street at I-75 and Spring Street at I-16 interchanges with and without the half diamond interchange at Riverside Drive. It was shown that the only intersection where the (LOS) improved was the I-75 NB exit ramp at Forsyth Street. Norfolk Southern Railroad Relocation MAAI has performed a study to assess the changes that would be necessary to the I-16/I-75 interchange project in order not to preclude a separate project to relocate the Norfolk Southern railroad. Four possible alternatives for the railroad relocation were looked at as part of this informal study. These alternatives included:
After a brief discussion of the pros and cons for each alternative, it was concluded that relocation of the railroad within the limits of the project would not be feasible due to the elevation changes necessary to span the Ocmulgee River at the 100 year flood stage. Miscellaneous Alternatives E-mail was received requesting GDOT to examine a left hand exit from I-75 SB to Riverside Drive via the K-Mart parking lot. Neither GDOT nor FHWA would approve a design with a left hand exit from the interstate. The geometric of such a ramp would be undesirable and it would be difficult to prevent motorists from accidentally turning onto the ramp from Riverside Drive and going the wrong way. A committee member asked about the possible Emery Highway Flyover Bridge to I-16. It was intended to have the ramp extend from Emery Highway SB directly to I-16 WB, which would alleviate traffic at the Spring Street intersection. The analysis of this shows a connection from I-16 EB to Emery Highway NB. Essentially the same problems would result. Grade changes on Emery Highway would be severe. In addition, this ramp would create a bad-weaving section on the WB collector distributor (CD), introducing a full interchange at Second Street would accomplish this same movement and at a much cheaper cost. Concept Alternatives - Analysis & Selection The six alternative concepts and the initial concept (prepared by GDOT for cost estimating purposes) were reviewed briefly. The committee due to the following fatal flaws eliminated four of these alternatives:
The remaining three conceptual alternatives (1, 2, & 3) and a new hybrid concept (Alternative #7) were then discussed. Line diagrams and the goals matrix were used to discuss the pros and cons of the remaining alternatives. Alternative #1 - Alternative #1 was discussed in detail with several engineers from the consultant team offering explanations of various design criteria. The following is a list of the areas that the consultant outlined as needing improvement:
Although none of the problem areas mentioned were considered fatal flaws, it was agreed that Alternative #1 needed improvement. Alternative #2 - It was pointed out that the primary goal with Alternative #2 was to reduce construction costs and decrease the footprint of the project by eliminating the braided ramps. To accomplish this, the ramp from Spring Street to I-16 EB was routed through an at-grade intersection with 2nd Street. The traffic studies showed that this intersection, as shown in Alternative #2, would operate at a LOS of F. Alternative #2, despite several desirable features, was therefore eliminated. Alternative #3 - This alternative was shown to have some of the same positive features as Alternative #2 (reduced footprint and reduced construction costs), but some of the same negative features as Alternative #1 (poor signage, bad weave on CD road, non-directional split, and bad merge at I-75 SB). The traffic study for this alternative showed that the proposed Spring Street/EB CD road intersection would operate at a LOS of E. Since the objective of these roadway improvements is to achieve LOS D or better, Alternative #3 was formally eliminated. Alternative #7 - Alternative #7 was then introduced to correct the deficiencies described in Alternative #1 while incorporating several positive features from Alternatives #2 and 3. The following is an outline of the problem areas from previous alternatives and how Alternative #7 corrects or improves these areas:
The Advisory Committee agreed to move forward with Alternative #7 as the preferred alternative. "Parking Lot" and Follow-up Items There were a few more topics added to the "parking lot" that could not be addressed at this meeting, or should be considered for future meetings. These included:
In closing, it was agreed that the committee would meet before the next public meeting. Details regarding the time and location of the next committee meeting and the PIM will be provided at a later date. The meeting was adjourned to a future date to be determined prior to a second Public Informational Meeting. |
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