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HomeMy WebLinkAboutM-80-0002Mr. Joseph R. Grassie City Manager City of Miami 3500 Pan American Drive Miami, Florida 33133 Re: Miami Stadium/Miami Garment District Interchange Study - 79138 Attention: Ms. Angela Bellamy DAVID PLUMMER & ASSOCIATES INC, CONSULTING ENGINEERS TRAFFIC • PARKING TRANSIT • HIGHWAYS ACCIDENTS • ZONING Decemaer 10, 1979 Dear Mr. Grassie, I have recently completed a feasibility study for improving freeway access to the Miami Stadium and Miami Garment District areas for the City of Miami Departments of Public Works and Planning. All of the aspects of the agreement between the City of Miami and my firm have been fulfilled and the results of that analysis documented. I would appreciate an opportunity to make an individual appearance at the City of Miami Commission on the regularly scheduled meeting of January 10th to briefly review the results of the study. Please notify my offices of the time of my appearance when you finalize the agenda for that meeting. i DSP:mtu cc Mr. Don Cather Very�trt'l� y/ ►t�;,��1 David S. 'Plummer CD CV r-'t 77. es ca 2355 SALZEDO ST. ORAL GABLES, FLORIDA 33134 • ELEPHONE (305) 444-2116 1 80-2 Joseph R. Grassie City Manager ...—.' sr' Donald W: Cattier Director of Public Works r'- January 4, 1980 Miami Stadium/ Miami Garment District Interchange - 1-95 Map of Area The firm of David Plummer & Associates, Inc. was retained by the City Administration to study the feasibility of providing additional access to 1-95 in the Miami Stadium / Miami Garment District area. Mr. Plummer has now completed his work, and is scheduled to make a formal presentation to the City Commission on Jan. 10, 1980. The study reviewed four possible types of interchanges. The most feasible was found to be a partial diamond interchange serving traffic to and from the north at N.W. 20th Street. This was dictated by the weaving distances required for safe traffic movement. Traffic to and from the south would be served by the existing ramps south of N.W. 20th Street. The proposed ramps at N.W. 20th Street have been reviewed by the staff of the Florida Department of Transportation and have been referred to FDOT's consultants, H. W. Lochner, Inc., who are currently evaluating overall 1-95 interchange operations in the City of Miami. This evaluation includes the recurrent congestion that occurs at the N.W. 14th Street interchange with State Road 836. r., Mr. Donald W. Cather Director of Public Works P.O. Box 330708 Miami, Florida 33133 t;. P" 10: 51,.. DAVID PLUMMER & ASSOCIATES INC. CONSULTING ENGINEERS TRAFFIC • PARKING TRANSIT • HIGHWAYS ACCIDENTS • ZONING January 4, 1980 Re: Miami Stadium/Miami Garment District Interchange - 79138 Dear Don, Enclosed are the items that you requested for distribution to the City Commission. The items are as follows: 1. Descriptive letter of project conclusions dated November 1 1979. 2. Supplemental letter regarding project conclusions dated December 10, 1979. 3. 81/2 x 11 schematic showing area of influence and interchange types. As you requested I have reserved January loth for the presen- tation to the City. Please have your secretary notify my office as soon as the time for my presentation becomes known. DSP:mtu enclosures Very truly yours, David S. Plummer 11) r✓�� C < �� c :*frcL l 2355 SALZEDO ST. CORAL GABLES, FLORIDA 33134 TELEPHONE (305)444.2116 Mr. George Deakin H. W. Lochner, Inc. Consulting Engineers 9720 Executive Center Dr., North St. Petersburg, Florida 33702 Re: - r , d a DAVID PLUMMER & ASSOCIATES INC. CONSULTING ENGINEERS TRAFFIC • PARKING TRANSIT • HIGHWAYS ACCIDENTS • ZONING November 19, 1979 Miami Stadium/Miami Garment District Interchange - 79138 Dear Mr. Deakin, I appreciated your attending the November 1st meeting with the Florida Department of Transportation, the City of Miami and my firm at which time we discussed the various technical as- pects of the Interchange Feasibility Study for Interstate 95 between State Road 836 and the Julia Tuttle Causeway. This letter fulfills the Florida Department of Transportation's request that we advise your firm of our conclusions and pro- vide the analysis sheets which document our findings. The objective of the City of Miami Study was to assess the feasibility of providing an additional interchange on Inter- state 95 between the north south limits previously described. It was recognized early in the project that substantial weaving presently exists between the Julia Tuttle Causeway and State Road 836 and that an additional interchange between these two freeways would contribute to•this condition. However, since there are two other major transportation advantages to additional access in this area these advantages must be com- pared to the quantifiable disadvantages of the weaving situation. These advantages are as follows: 1. Recurring congestion is evident on the southbound exit ramp between Interstate 95 and State Road 836. This congestion is partly a result of the high trip demand generated by the employment centers in the area of the Dade County. Justice Center and Jackson Memorial Hospital. Access to these locations from north and south Interstate 95 is only available at the State Road 836 interchange with N.W. 12th Avenue. The single traffic signal operation at that locatici: does not have the capacity necessary to respond to this magnitude of vehicle demand. The congestion is also affected by the weaving section created by the west- bound vehicles from north and southbound Interstate 95. An additional interchange would intercept much of this em- ployment travel demand and would reduce the magnitude of recurring congestion. 2355 SALZEDO ST. CORAL GABLES, FLORIDA 33134 TELEPHONE (305) 444.2116 Mr. George Deakin 2 November 19, 1979 2. The Miami Garment District and Miami Stadium areas, lying east and west of Interstate 95, are undergoing tremendous growth. The Garment District is the City of Miami's most vibrant industrial district with new industries constantly moving into this area. The City is spending a great deal of revitalization effort with plans for parks, elderly housing and other community necessities. The Miami Stadium area, west of Interstate 95, is under- going the same type of redevelopment pressures. Access to these sections is completely denied by virtue of the physical barrier created by the location of the east/west and north/south access controlled freeways. Travel into these sections, both from the north and south, is required to exit from the freeway at access points com- pletely remote from their destinations. An additional interchange. along Interstate 95 would provide more reason- able access. In preparing our data base we relied extensively on the traffic counting efforts you had expended for the overall Interstate 95 Study. Our specific concerns were, of course, the entering and exiting ramp volumes which presently create the weaving sections. I have attached to this letter, marked as Exhibit A, a rough draft of the a.m. and p.m. hourly volumes for these ramps as supplied by your. organization. We have verified these volumes with manual counts and feel that the present day volumes shown on Exhibit A reasonably portray actual vehicle demands. The next step.in our analysis was to develop several interchange types which would provide the required service to these areas. Approximately six different configurations were developed with the City of Miami ultimately indicating that the following three types should be studied in more detail: 1. Split Diamond Interchange utilizing N.W. 29th Street for movements to and from the south and N.W. 20th Street for movements to and from the north. 2. Partial Diamond Interchange providing service to and from the south only at N.W. 29th Street. 3. Partial Diamond Interchange providing access to and from the north at N.W. 20th Street. 4. Mid -Block Interchange with access on the west side at N.W. 24th Street and on the east side at N.W. 23rd Street. Mr. George Deak e'• 3 November 19, 1979 Utilizing these interchange configurations and the southbound a.m. and northbound p.m. peak hour volumes, the various mul- tiple weaving sections created by the additional interchange were analyzed. In this regard there are two philosophies regarding weaving sections.' The first, contained in the Highway Capacity Manual, 1965, is the more liberal of the analysis procedures and allocates portions of weaving volumes to the different sections based on the distance between the ramp gores. The second method, which will be called the Jack Leisch/Traffic Institute Methodology, utilizes the same weaving chart but does not provide for a reduction in the weaving volume in the second segment due to the weaves that took place in the first. In our analysis we utilized both methods and then compared the results. A third weaving condition, des- cribed in NCHRP-159, is rumored to be the basis for a forth- coming revised Highway Capacity Manual but as of this gate it appears to have no official national recognition. The worksheets showing the results of our weaving calculations are also attached to this letter and marked as Exhibits 2 through 8. The Traffic Institute form was used for both the Highway Capacity Manual and the Jack Leisch/Traffic Institute approach. The volume which will utilize the new ramp and the subsequent diversion from the existing ramp movements, are attached as Exhibits 9 through 10. The results of the weaving analysis is as follows: 1. The Split Interchange with access from N.W. 29th Street and N.W. 20th Street provides unacceptable weaving con- ditions on Interstate 95. 2. The Partial Interchange with access to and from the south at N.W.. 29th Street provides unacceptable weaving on Interstate 95. 3. The Partial Interchange providing access to and from the north at N.W. 20th Street provides acceptable weaving conditions under the Highway Capacity Manual approach. It does not provide acceptable weaving when the conditions are analyzed utilizing the Jack Leisch/Traffic Institute approach. 4. The Mid -Block Interchange, with the ramp gores located in more undesirable locations, also provides unacceptable weaving conditions. The weaving maneuvers on Interstate 95 in. this area are required to cross two lanes and had to be analyzed as a "compounded" condition. This "compounded" condition is related to the weaving chart contained in the Highway Capacity Manual by using the "desirable" Quality of Flows for Level of Service D, the assumed condition on'Interstate 95, rather than the "Minimum" condition. Mr. George Deakin 4 November 19, 1979 In doing any type of feasibility study certain assumptions have to be incorporated into the analysis. The results of this particular study, which found the Partial Interchange for traffic to and from the north at N.W. 20th Street acceptable, were based on the following conditions and assumptions. If these assumptions vary then the technical conclusions may also vary. ' 1. The Highway Capacity Manual weaving calculation methodology is acceptable to the various review agencies. 2. The traffic growth on Interstate 95 and the appropriate area ramps will be offset by the diversion of peak hour trips to the Transit System. 3. The right-of-way requirements in the northeast and north- west quadrants of the intersections of Interstate 95 with N.W. 20th Street can be reserved and will ultimately be available. 4. The traffic assigned to the new interchanges, which was based on engineering judgement, is reasonably consistent with the volumes your organization will ultimately assign based on a detailed Origin and Destination Survey. The City of Miami is hopeful that a Partial Interchange solution for additional access in this area will be incorporated into your overall Interstate 95 Master Plan. The Florida Department of Transportation had tentatively indicated that your analysis would be completed within 12 months, deducting the time required for approval of your environmental studies, and that your comments would be available before that time. If a favorable result is received within that time frame then the landuse plan for this area could be adjusted to, the access improvements. My firm stands ready to provide whatever assis- tance might be necessary to assist your organization or the Florida Department of Transportation in this evaluation. Lastly, we feel it is important for the various public reviewing agencies to recognize the recurring congestion on southbound Interstate 95 at State Road 836 and to weigh that against shorter weaving lengths created by the additional interchange. If the decision regarding the interchange is based solely on an office evaluation of weaving conditions it is possible that the conclusion would not be consistent with the field conditions. Since the State Road 836 ramp backs onto the main line for a distance of over 1500 feet during lengthly periods in both the morning and the evening peak hours the actual Mr. George Deakil 5 November 19, 1979 length available to weave under today's conditions is reduced accordingly. An additional interchange at N.W. 20th Street, which would intercept a majority of this volume destined to the previously described employment centers, would provide an opportunity to return the State Road 836 ramp and the Interstate 95 main line to an acceptable operating condition. We are hopeful that you will keep this comparison in mind when reviewing this feasibility request. Looking forward to continuing association and other members of your organization, I remain, Very truly yours, David S. Plummer DSP:mtu cc Mr. Donald W. Cather, letter only Mr. Armando Vidal, letter only Mr. George Deakin H. W. Lochner, Inc. Consulting Engineers 9720 Executive Center Dr., North St. Petersburg, Florida 33702 Re: Miami Stadium/Miami Garment District Interchange Study - 79138 DAVID PLUMMER & ASSOCIATES INC. CONSULTING ENGINEERS TRAFFIC • PARKING TRANSIT • HIGHWAYS ACCIDENTS • ZONING December 10, 1979 Dear George, Please be advised that my firm's presentation to the City of Miami Commission regarding the feasibility of an additional interchange on Interstate 95 in the area of the Miami Stadium/ Garment District is tentatively scheduled for January 10, 1980. The presentation should take no longer than ten minutes and is simply to inform the Commission that one interchange type might be feasible under some very structured assumptions. I will inform the Commission that the Florida Department of Trans- portation and your firm are carrying the study to a finer degree of refinement. I have also reviewed the National Cooperative Highway Research Program Report 159 (Weaving Areas - Design and Analysis) which was completed in 1975. This report utilizes a completely. new approach to analyzing weaving sections'and states that the weaving maneuvers segregate into very definable areas prior to approaching the segment ramp gores. The advantages to this approachas related to our analysis is that the weaving taking place in Segment 1 is completed prior to arriving at Segment 2. The disadvantage is that the individual weaving maneuvers are concentrated into those individual segments. I have not been authorized by the City of Miami to extend our study to include this new technique but I will request that authorization in the very near future. One area that I did not include in my previous correspondence was consideration of grade separations for the weaving maneuvers. In our original discussions with the City of Miami we had eliminated these costly interchange types. I think my previous correspondence implied that the only interchange that would, 2355 SALZEDO ST. CORAL GABLES, FLORIDA 33134 TELEPHONE (305) 444.2116 Mr. George Deakin 2 December 10, 1979 work was the partial diamond located at N.W. 20th Street. In terms of low cost interchanges this is true. However, if the Florida Department of Transportation and the Federal Highway Administration were willing to fund the rather lengthy structures needed to physically separate some of these weaving maneuvers then additional high -cost interchange types would also be feasible at this location. Very truly yours, David S. Plummer DSP:mtu cc Mr. Don Lather Mr. Armando Vidal 77 N.T.S. MIAMI STADIUM SPLIT DIAMOND - A a C HALF DIAMOND ( 29 ST.) -A HALF DIAMOND (20 ST.) -C MID -BLOCK - B MIAMI STADIUM/MIAMI GARMENT DISTRICT INTERCHANGE STUDY CIVIC CENTER EAST/WEST IIIIIIIIIII II zz N.T.S. I95 ›- a. x W a cc Q MIAMI GARMEN DIST. MIAMI STADIUM SPLIT DIAMOND - A a C HALF DIAMOND (29 ST.) - A HALF DIAMOND (20 ST.) - C MID -BLOCK - B MIAMI STADIUM/MIAMI GARMENT DISTRICT INTERCHANGE STUDY M co . cc cn CIVIC CENTER EAST/ WEST