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White St Pro P H FollowupMEMORANDUM April 11, 2002 TO: FROM: SUBJECT: The Honorable Mayor and City Council Members Michael C. Van Milligen, City Manager White Street Reconstruction Project - Public Hearing Follow-Up Public Works Director Mike Koch submits the attached memo to provide follow-up information on several questions left unanswered at the conclusion of the public hearing on the White Street Reconstruction Project from 21st to 32nd Street. Michael C. Van Milligen MCVM/jh Attachment cc: Barry Lindahl, Corporation Counsel Cindy Steinhauser, Assistant City Manager Michael A. Koch, Public Works Director CITY OF DUBUQUE, IOWA MEMORANDUM April 10, 2002 TO: FROM: SUBJECT: Michael C. Van Milligen, City Manager Michael A. Koch, Public Works Director White Street Reconstruction Project - Public Hearing Follow-Up INTRODUCTION The public hearing on the White Street Reconstruction Project from 21st to 32nd Street was held by the City Council on January 21, 2002. Even though the project was approved, there were several questions left unanswered at the conclusion of the hearing. BACKGROUND The unresolved issues are summarized as follows: Can White Street be narrowed to 37 feet in width in the 22nd to 24th Street blocks? This is intended to slow down the perceived excessive speeding in these blocks. Can the proposed pavement thickness between 22nd and 24th Streets be decreased from the proposed 8" thickness to 7" as it the balance of the project? Can the advance signage be improved to better direct motorists and truckers to turn left at 21st Street, which is the marked truck route? Can the horizontal offset of White Street at 22nd Street be lessened to improve the traffic flow to motorists crossing 22nd Street at White? 5. Can the City limit the number of trucks on White Street between 21st and 24th Street? DISCUSSION 1. Street Width The Engineering Division's review of the plans for paving of the section of White Street between 22nd and 24th street indicates that there should not be a problem in narrowing the proposed pavement width from 41' to the requested 37-foot width. Traffic volumes in this two-block area were found to be 585 vehicles per day southbound on White Street and 1,083 vehicles northbound. The 85th percentile speed, which is the speed normally considered when performing speed studies, is 25.0 m.p.h, for southbound traffic and 26.6 m.p.h, for northbound traffic. This is consistent with the street's posted 25 m.p.h, speed limit. There were speeds in excess of 25 - 26 m.p.h.; however, these numbers were small in comparison to the total volume of traffic on the street. No further action is felt to be necessary to control traffic speed on White Street between 22nd and 24th Street. The City's experience on the reconstruction of the City streets is that traffic speeds do not increase after the completion of a paving project. This has been documented over several years by performing "before" and "after" speed studies. 2. Pavement Thickness The total daily traffic on White Street from 22nd to 24th Street is 1,668. This is equivalent to a medium volume local residential street. There should, therefore, be no problem in decreasing the proposed pavement thickness to 7", which would be consistent with the balance of the project. 3. Signage The Engineering Division's review of signage did indicate that a couple of changes were in order. A maP is enclosed showing these changes and their location. First, a "No Trucks Over 5 Tons Licensed Weight" sign was installed for northbound traffic immediately north of 21st Street. (Trucks are prohibited in this block of White Street unless making local deliveries.) This should require trucks to either follow the marked truck route over to Central Avenue or to turn eastbound on 21st to Jackson Street. Qne set of improperly-placed lane use signs was also removed. An additional "No Truck" sign will be placed for northbound traffic north of 22nd Street. This would be identical to the newly-placed sign at 21st Street. As can be seen on the map, there are already advance signs between 19th and 20th, and between 20th and 21st Street indicating the proper lane usage to follow Highway 52 north to Central Avenue. The placement of these signs was also reviewed by the Iowa Department of Transportation since this is a marked highway route. Both IDOT and the City feel that with the changes indicated the signage should be up-to-date and appropriate for the situation. The Engineering Division also looked at modifications to the existing island at the intersection of 21st and White Street to determine if it should be made larger in order to slow northbound traffic in the 21st to 22nd Street block and to keep trucks from continuing on White Street north of 21st Street. As can be seen on the enclosed photograph, the existing concrete island is about as large as it can be to safely pass by the median with sufficient clearance. If the island were enlarged to the east, parking would have to be removed from the east side of White both north and south of 21st Street to allow for sufficient clearance. This would, however, defeat the purpose of the widening of the island, since vehicles would then not be required to slow down to continue this northbound movement. Similar to the other section of White Street, the existing 25 m.p.h, speed limit is appropriate for this block, with vehicles traveling 27.5 m.p.h, for the 85t~ percentile speed northbound and 24.7 m.p.h, southbound. This flow of traffic northbound past 21st Street appears deliberate according to the traffic volumes taken in this area. Fifty-five percent (55%) of this northbound traffic is destined for 22nd Street and does not continue northerly beyond this point. 4. Horizontal Offset at 22nd Street The Engineering Division has reviewed the current offset in the curb lines of White Street from the south side of 22nd to the north side. The reason for the offset is unclear, but it is clear that even with narrowing of White Street to 28', the offset cannot be made significantly smoother than it currently is without the purchase of additional right-of-way. This is because we are still working on the same right-of-way width of both sides of 22nd Street and the narrowing of White Street north of 22nd only results in a total curb offset of 3'. Attached is a plan of the current configuration of the intersection. The plans to narrow White Street provide for the east curb to be moved 3' westerly, creating an offset roadway within the right-of-way. If the narrowing were to be made equally on both sides of the street, the offset between the curbs would become even greater. Also attached is a plan showing the amount of right-of-way which would be needed to align the centedines of White Street across 22nd Street. 5. Truck Usage The issue of truck usage was addressed in Paragraph 3. ACTION TO BE TAKEN The City Council is requested to review the responses of the City staff to the issues left outstanding at the conclusion of the public hearing and to give direction to City staff on how to proceed on the various issues. MAK/vjd cc: Michael Felderman, Civil Engineer Bill Schlickman, Engineering REFERENCE: White Street Average Annual Daily Traffic 1. Street Width Palle~SUl P9lle;SUl a8 o J_ o~ 22nd 0