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Transportation Advisory Commission Agenda 02-12-2004I-94/CSAH 18 Interchange Meeting with FHWA Interchange Type St. Paul, MN Thursday, February 12, 2004 Meeting Minutes ATTENDANEES: David Graeber Jim McCarthy Terry Peterson Chad Hausmann Wayne Fingalson Virgil Hawkins Doug Weiszhaar Brandi Popenhagen Tony Heppelmann 1. Interchange Need FHWA FHWA Mn/DOT Dist. 3 Mn/DOT Dist. 3 Wright County Wright County WSB & Associates, Inc. WSB & Associates, Inc. WSB & Associates, Inc. • As the City of Monticello continues to grow, the demand to go east and west on I-94 will continue to grow. Only one interchange located at TH 25 provides full access to I-94 in the City. A partial access exists on CSAH 75 but only provides access east, to and from the Twin Cites. An Interchange Access Request (IAR) was completed and approved in 2000 to provide a full interchange access to I-94 at CSAH 18 to replace the partial access at CSAH 75. This report showed an interim stage of the interchange where CSAH 75 ramps would be left open providing access to and from the east. New ramps would be provided at CSAH 18 to accommodate the demand to and from the west. The report showed the ultimate interchange configuration would occur at CSAH IS with a standard diamond for the westbound (WB) ramps and folded diamond to the east for the eastbound ramps. Prior analysis documented in the 2000 IAR indicated that if no additional improvements are made to the supporting transportation system by 2020, the westbound I-94 ramp intersection with TH 25 would operate at a level of service (LOS) F during the P.M. peak hour. 2. Interchange Alternatives • Alternative I — No Build. Leave the existing partial access at CSAH 75, and do not provide additional ramps for access west. Page I of 4 C:Awindows\TEMP\Feb 12 2004 Minutes Interchange Selection with FHWA.doc I-94/CSAH 18 Interchange Meeting with FHWA February 12, 2004 • Alternative 2 — Folded Diamond Interchange to the east in both quadrants. The interchange alternative is different than the one approved in the 2000 IAR by folding the WB ramps to the east. This alternative includes the extension of 7th Street to CSAH 18 opposite the WB ramp terminals. Seventh (7th) Street is a Municipal State Aid route and its function would serve as a parallel collector/arterial to CSAH 75. Its connection to CSAH 18 is consistent with the Monticello Transportation Plan currently being updated. A commercial development is anticipated between CSAH 75 and 7th Street near CSAH 18. Another access is proposed on CSAH 75 just west of CSAH 18 to relieve traffic at the proposed CSAH 18/71h Street intersection. The access is currently named Vertical Road. • Alternative 3 — Approved Interchange Alternative. As mentioned above, this alternative folds the diamond east in the southeast quadrant with a standard diamond configuration for the WB ramps. Seventh (71h) Street would connect into CSAH 75 at the same location that Vertical Road connects into CSAH 75 in the previous alternative. • Alternative 3a — Approved Interchange Alternative with two WB exit ramps. This interchange configuration would be similar to Alternative 3 but would add an additional WB exit ramp to CSAH 75 just prior to the WB exit ramp to CSAH 18. The intent for the additional exit to CSAH 75 would be to reduce the left turns from northbound (NB) CSAH 18 to WB CSAH 75. Instead the left turns would be through movements at the CSAH 18/75 intersection. 3. Interchange Operations Analysis FHWA is concerned that the spacing between the proposed CSAH 18 westbound ramp terminals and the next northern intersection of CSAH 18/CSAH 75 is too short. Delays from the CSAH 18/75 intersection could cause traffic to spill back onto I-94. WSB & Associates Inc. (WSB) analyzed the three interchange alternatives based on preliminary forecasted 2025 P.M. peak hour volumes. These volumes were generated from the travel demand model currently being updated for the City of Monticello. • Alternative 1 — No Build. As mentioned above, the WB I-94 ramp intersection with TH 25 would operate at a LOS F during the P.M. peak hour. The signal analysis showed the CSAH 18/75 intersection also operated at a LOS F. • Alternative 2 — Folded Diamond Interchange to the east in both quadrants. The LOS at CSAH 18/71h Street and CSAH 18/CSAH 75 intersections are C and B respectively. This indicates the probability of back-ups spilling onto I-94 are lowest for Alternative 2 when compared to Page 2 of 4 C:\windows\TEMP\Feb 12 2004 Minutes Interchange Selection with FHWA.doc 1-94/CSAH 18 Interchange Meeting with FHWA February 12, 2004 all other Build alternatives analyzed. Seventh (7th) Street provides a reliever to CSAH 75 and reduces the demand for left turns from NB CSAH 18 to WB CSAH 75. o FHWA stated that the access for Vertical Road on CSAH 75 requires an at -grade crossing with the railroad. FHWA would need verification that the City of Monticello has secured the new grade crossing before approving the interchange configuration. FHWA would like WSB to analyze the impacts to CSAH 18 interchange without the Vertical Road access on CSAH 75 as well. • Alternative 3 — Approved Interchange Alternative. The LOS Tables handed out were mislabeled. The 4th Table should be labeled `Build 3". The LOS at CSAH 18/WB Ramp Terminals and CSAH 18/75 are E and B respectively. The drawback of this alternative is all of the traffic desiring to use WB CSAH 75 or 7"' Street (at the Vertical Road access) would have to turn left from NB CSAH 18 to WB CSAH 75. Out of all of the build alternatives, Alternative 3 would have the highest probability of traffic back-ups spilling onto I-94. o FHWA requested that WSB consider a 1-way in only to 7th Street at the WB I-94 Entrance ramp intersection with CSAH 18. Seventh (7th) Street and the entrance ramp would split after the intersections with CSAH 18. ■ Terry Humbert believed Mn/DOT Central Office was no longer in favor of tying ramps and frontage road together. ■ If 7th Street is a 1-way in only, EB traffic destined south of CSAH 18 along 7th Street would have to use Vertical Road to CSAH 75, then right onto CSAH 18, and would add to the through movement at CSAH 18/WB Ramp Terminal intersection. Because of the large increase in through movement, the intersection would likely perform worse than Alternative 2. WSB will analyze to verify. • Alternative 3a — Approved Interchange Alternative with two WB exit ramps. The LOS Tables handed out were mislabeled. The 3rd Table should be labeled `Build 3a". The LOS at CSAH 18/WB Ramp Terminals and CSAH 18/75 intersections are B and D respectively. The intersection at CSAH 18/75 performs worse because the additional WB through movements conflict the NB CSAH 18 left turns. Since Monticello is anticipated to grow mostly south of I-94, there will be a large demand for traffic coming from the south along CSAH 18 to downtown Monticello Page 3) of 4 C:Awindows\TEMP\Feb 12 2004 Minutes Interchange Selection with FHWA.doc I-94/CSAH 18 Interchange Meeting with FHWA February 12, 2004 (which is northwest). Adding the additional ramp will only relieve the demand generated from the freeway. o Mn/DOT intends to sever CSAH 75 under I-94 if Mn/DOT realigns I-94 to shorten the bridge lengths across the railroad. If CSAH 75 is severed, the I-94 exit ramp that connects into it would no longer require a T-intersection. Instead, the exit ramp would become CSAH 75. Just east of CSAH 18, is a local road access onto CSAH 75 that would be maintained. If the exit ramp becomes CSAH 75 that has two-way traffic, a motorist could confuse the exit ramp portion of CSAH 75 as a two-way road and continue up the exit ramp into wrong way traffic on I-94. Motorists anticipate a return movement when leaving the freeway. This alternative would not allow a return movement to the freeway via CSAH 75, which is another reason a motorist may confuse the 1-way exit ramp as an option for entering the freeway. 4. Conclusions: WSB & Associates, Inc. will analyze the two additional alternatives and report back to FHWA with a memo of the analysis and conclusions. Page 4 of 4 CAwindows\TEMP\Feb 12 2004 Minutes Interchange selection with FHWA.doc