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HomeMy WebLinkAbout1999-250 Memo - Kittelson & AssociatesCITY OF ASHLAND Department of Pubic Works Public Works Administration DATE: TO: FROM: RE: MEMORANDUM November 8, 1999 Paula Brown, John MacLaughlin, Greg Scoles, Keith Woodley, Scott Fleuter, Pieter Smeenk, Ray Smith, Traffic Safety Commission James H. O~son, Engineering Services Manager ~ // INTERSECTION STUDY FINAL REPORT v Attached is a copy of the final report, prepared by Kittelson & Associated, Inc. for the study of the. Lithia Way, E. Main Street, Siskiyou Blvd., Third Street intersection. There are four options presented in the study which should be further studied. The Kittelson report makes no specific recommendations. G:Dawn\Tra¢,E Main Intersection Final Report Memo doc KITTELSON & ASSOCIATES, INC. TRANSPORTATION PLANNING/TRAFFIC ENGINEERING 610SWALDER~SUITE 700 · PORTLAND, OR 97205 · (503) 228-5230 ° FAX (503) 273-8169 November 3, 1999 Mr. James H. Olson. Engineering Services Manager City of Ashland Department of Public Works 20 East Main Street Ashland, OR 97520 RE: Technical Assistance Program--Final Memorandum Dear Jim. It has been a real pleasure to work with you and the other Ashland staff on this evaluation. Enclosed please find 8 copies of the final memorandum. I would be happy to answer other questions should they arise. Once again, thank you for the opportunity to work with you. We hope xve can be of assistance in the future with this location or other projects in the Ashland area. Please call me at 503 228- 5230 if I can answer additional questions. Sincerely, Kittel~nn & Associates, Inc. Brian L. Ray, P.E. Enclosures H:\projfile\3828\corres\final. DOC KITTELSON & ASSOCIATES, INC. TRANSPORTATION PLANNING/TRAFFIC ENGINEERING 610 SW ALDER, SUITE 700 · PORTLAND, OR 97205 · (503) 228-5230 ' FAX (503) 273-8169 Date: To: From: TECHNICAL MEMORANDUM City of Ashland--Technical Assistance Program Highway 99/Main Street Intersection Evaluation Design and Operations Opportunities November 1, 1999 Mr. James H. Olson Brian L. Ray, P.E. Project #: 3828 OVERVIEW ' The Highway 99 couplet terminal at Main Street is typical of its era with respect to its geometric layout. The roadway was constructed to minimize physical impacts resulting in constrained geometrics, poor intersection angles, and numerous access points including driveways and alleys. Over the years as traffic volumes have grown and travel patterns have changed, the operations of the roadway has degraded. As Ashland has prospered into a cultural and recreational center, the land uses have changed and pedestrian activities have increased. The existing intersection and roadway system no longer fits with current and future land uses. Figure 1 depicts a Site Vicinity Map. This memorandum highlights key issues and opportunities for future project development activities to improve the intersection. Intersection improvements could be coordinated with current plans for the library expansion, new fire station, and the downtown parking and pedestrian study programmed as part of the Transportation Growth Management (TGM) program. EXISTING CONDITIONS Siskiyou Boulevard (Hwy. 99) and the couplet provide adequate capacity to serve the downtown area. Fundamentally, these two parts of Hwy. 99 serve distinct functions and have corresponding different operating characteristics. Siskiyou Boulevard serves as a significant arterial providing high mobility. Its relatively limited access and raised median provide high capacity and operating speeds. Figure 1 shows the site and vicinity. The couplet, typical for downtown areas, emphasizes accessibility and provides access to business. The area has a high number access points, on street parking, and associated pedestrian FILE: HSPROJFILE\3828\CORRES\SUMMEM.WPD Project Number: 3828 City of Ashland--Technical Assistance Program TECHNICAL MEMORANDUM Highway 99/Main Street Intersection Evaluation Design and Operations Opportunities DATE: November 1, 1999 PAGE: 2 activity. The conflict appears in the transition between facility types and the competing characteristics of mobility and accessibility. Drivers on Hwy. 99 do not have adequate time to adjust their speed and operations between the divided arterial and the downtown couplet. Resolving conflicts of this type usually take the form of increasing driver awareness of appropriate operations and speed management. Drivers entering the City from Siskiyou Boulevard inherently exceed posted speeds. This behavior is consistent with the roadway characteristics (alignment, cross section, median, managed access) on Siskiyou Boulevard. Not until drivers enter the couplet do the visual clues of on street parking, traffic signals, and pedestrians result in a slowing of travel speeds. Southbound drivers leaving the City approaching Third/Gresham Streets see a widening of the roadway (to four lanes) and the long tangent section on Siskiyou Boulevard. This results in increased travel speeds near the library, still within the downtown core area. Unfortunately, the transition between the two facility types occurs in a location of undesirable intersection sk&w angles, constrained geometrics, and poor sight distance caused by the existing fire station. The gateway treatment at the couplet return is too late for advance warning. These conditions have resulted in documented accidents and many more near misses. In addition, the short distance on southbound Hwy. 99 between Gresham Street and the couplet return result in weaving traffic and unconventional lane changes. In the couplet, on-street track loading operations in the southbound direction effectively reduce the roadway cross section (and available capacity) to two lanes. Lane blockages can occur on either outside lane and result in numerous and excessive lane changes for through motorists. In short, the lane blockages degrade operations and increase vehicle and pedestrian conflicts as drivers change lanes. CONCEPT DEVELOPMENT Based on current proposals for the library, fire station, and future parking and circulation study, each of the concepts shown in the attached figures maintains the following characteristics: -- Shifting the "gateway" treatment south of the fire station to send visual clues to drivers that the facility type and function is changing; -- Closing the existing median and creating a new median opening for the fire station; -- Each concept incorporates the proposed fire station and library improvements; -- Reducing the number of lanes from four to three on southbound HWY. 99 between Gresham Street and the couplet return; FILE: HSPROJFILEL3828\CORP.-ES\SUMMEM.WPD Project Number: 3828 · uo~.lals o~ ,~ou Jo ~usls~.xo oql ql~.~ pola?ossa sNu~!s Kauo~omo `{ua qlVa polau!pJooo oq pua ~op!suoo plnoqs uo~l~ooI s!ql la uo[luz!Nu~.8 'uo~a poz!uaq~n u~olu~op oql ,puslxo,, ol pua 'KaAk a.~ql.~q punoqql.xou ol 1,oi18 u!elAI uloI,I SlUOtUOAOtU JoJaS ,,aolIa 'su2!alsspsd ~oj sda~ i~msso~o op.x^o~d ol suoolqd slusxo pinoo I*U~!S sq£ '(spuoq IaUi!S pue '~u!~uua q~tltlI~tS OOL!BApl~ olul~doIddu ql!~) laU~!S o~Jml ~ [[ulsu! ol qs!~ `{utu l! 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These changes increase the sight distance to the new fire station, reduce speeds for southbound drivers, provide excellent pedestrian crossings, and provide parking and landscape opportunities in front of the library. All of this is accomplished by using the available median space. The signal would potentially operate using two-phase control, depending on the number of left tums using the couplet return lane. In theory, the intersection size could be farther reduced by bringing the southbound roadway closer to the Main Street approach alignment. In effect, the alignment would create an intersection where the southbound roadway "Tees" into the northbound roadway. A conventional left-turn lane would replace the couplet return and the through movement would continue across the northbound roadway to Main Street. Because of volumes, two right turning lanes would be required to southbound Siskiyou Boulevard. With further modification, left turns could be provided from Main Street to southbound Hwy. 99. This would eliminate the out of direction movement to southbound Hwy 99 that presently occurs via northbound HWY 99 and Third Street. This would increase the overall size of the intersection and the number of signal phases required to serve traffic. UNSIGNALIZED INTERSECTION Past studies have indicated the present intersection wilI operate acceptably during the planning horizon. The m/nor cross street movement will reach Level of Service (LOS) F based on delay, but not by volume to capacity. This means there are relatively few vehicles on the minor street and that by a volume consideration, there is plenty of roadway capacity. However, those vehicles have few gaps in the traffic stream and must wait more than 80 seconds on average. Studies of other minor streets in the downtown area would probably yield similar findings. This is typical, and as long as the delay does not provide other problems such as excessive queues, LOS F by delay is not a significant issue. Therefore, unsignalized intersection forms are appropriate considerations at this location. Two unsignalized options are shown in Figures 4 and 5. Either of these concepts could eventually be signalized to realize the benefits of a traffic signal. Option 1 Option 1 closes the existing median opening at the fire station and relocates it south, consistent with the driveway location shown on fire station architecture layout sheets. This concept is shown in Figure 4. Closing the median helps simplify the "activities" that are occurring at the FILE: HSPROJFILE\3828\CORRES\SUMMEM.WPD Project Number: 3828 City of Ashland--Technical Assistance Program TECHNICAL MEMORANDUM Highway 99/Main Street Intersection Evaluation Design and Operations Opportunities DATE: November 1, 1999 PAGE: 5 couplet terminal. Southbound Hwy. 99 has been shifted away from the library to provide on- street parking along the entire library frontage (a bus stop could be located to the nearside of the intersection, across Gresham Street if parking in front of the library is desirable). One lane has been removed between Gresham Street and the couplet return. The plan shows bike lanes on Siskiyou Boulevard by reducing the median width. The net effect is improved driver awareness and slower speeds. The alley driveway exiting at Third Street could be closed and the access off of Lithia Way made two-way. The access and cross walk relationship is unconventional and potentially unsafe, should pedestrian traffic on Lithia Way increase. The cross walk could be rotated out of the access, perpendicular to the roadway. This would require eliminating some on-street parking. These changes are not critical to improve the study intersection, but are consistent with enhancing overall pedestrian movements. The concept shows potential pedestrian enhancements. Curb extensions and curb line modifications dan reduce pedestrian exposure and provide landscaping opportunities. The curb modifications at the Gresham Street intersection help reduce the crossing distance, reduce speeds for southbound traffic turning toward the library, and effectively increase the weaving distance bet~veen Gresham Street and the couplet return. While still a short distance, the three lane section and proposed lane alignment is an improvement over existing. Option 2 Option 2 is very similar to Option 1 and is shown in Figure 5. In fact, there may be numerous variations or components of each plan that could be implemented. Option 2 would operate essentially the same as Option 1. The primary difference is that Option 2 more closely maintains the southbound Hwy. 99 alignment past Gresham Street. Option 2 also includes pedestrian and bicycle enhancements. In this case, the southbound lanes have been reduced to two and a striped bicycle lane has been introduced. Curb extensions at Third Street are a benefit with the two lane section by reducing the potential for wrong way movements to Th/rd Street. Southbound drivers wishing to use the couplet return or reach Main Street would be required to make a lane change to get into the left lane. We have not determined specifically how the City might achieve two lane section. One scenario is to not develop the third lane in the downtown core. The southbound lane-add near the City offices at the Oak Street intersection could be eliminated. The present lane addition could be replaced with a right turn lane to a two-lane, southbound roadway. City staff clearly indicated track loading is a key issue in the couplet and the third lane provides reserve capacity FILE: HSPROJFILE\3828\CORRES\SUMMEM.WPD Project Number: 3828 City of Ashland--Technical Assistance Program TECHNICAL MEMORANDUM Highway 99/Main Street Intersection Evaluation Design and Operations Opportunities DATE: November I, 1999 PAGE: 6 when trucks block a lane. If the third lane is to remain, continuity in the two remaining lanes could be maintained if on-street truck loading was designate to only one of the outside southbound lanes. If the southbound portion of couplet was reduced to two lanes, the City may wish to consider on-street loading restrictions during peak periods (7:00-9:00 a.m.; 11:00 a.m.-l:00 p.m.; 4:00- 6:00 p.m.). Another option would be to eliminate some on street parking and provide designated truck loading zones between 7:00 a.m. and 6:00 p.m. Any potential lane reduction through the downtown area is a significant change. Parking restrictions or lane reductions and should be considered in the context of a comprehensive downtown parking and circulation analysis. SIGHT DISTANCE ISSUES Sight distance at Main Street to northbound Hwy. 99 is clearly an issue. The current fire department bdilding coruer limits the existing sight distance to about 175 feet. Based on a 35 mph posted speed, 350 feet would be desirable. In order to identify potential gaps, Drivers must pull beyond the cross walk. The proposed fire station offers a significant improvement over existing conditions. · With the new fire station and no changes to Main Street, the sight distance increases to about 260 feet. If speeds in advance of the couplet could be managed (signing, enforcement, cross section treatments, etc) to maintain 25 mph, the distance would be acceptable. With the new fire station and improvements shown with the proposed signalized intersection, the sight distance could be increased to about 315 feet. There were questions about the sight distance as it relates to the roadway profile of northbound Hwy. 99. Reviewing the topographic maps provided by the City, we believe the vertical alignment is not a significant issue. The improved set backs with the new fire station are the controlling factor. It appears that the northbound roadway crests in advance of the fire station and that an adequate distance would be provided if there were no building obstructions. These technical findings should be reviewed with more detailed survey information prior to final building design. Adjusting the northern most corner of the new fire station (adjacent to Hwy. 99) could further increase the available sight distance--with or without intersection improvements at Main Street. The City should carefully review fire station landscaping plans to ensure future plantings along Hwy 99 do not hinder sight distance. FILE: HSPROJFILE\3828\CORRES\SUMMEM.WPD Project Number: 3828 City of Ashland--Technical Assistance Program TECHNICAL MEMORANDUM Highway 99/Main Street Intersection Evaluation Design and Operations Opportunities DATE: November 1, 1999 PAGE: 7 GATEWAY TREATMENT A gateway treatment on Siskiyou Boulevard near or in advance of the fire station would move the effective transition area (from the arterial to the couplet) out of the couplet. This gateway treatment should be tied to continuous landscaping up to the couplet. Northbound drivers would have advanced notice of the changing roadway conditions prior to entering the downtown area. Southbound drivers would experience a continuation of the downtown area. The gateway treatment in combination with other pedestrian, bicycle, and on -street parking enhancements would passively assist in speed management. Gateway treatments can take a variety of forms but can include a landscaping and monument feature, vertical archways spanning the adjacent sidewalk, or relatively simple ornamental "Welcome to Ashland" signs with differentiating landscape treatments. FILE: H:~PROJFILE\3828\CORRES\SUMMEM.WPD Project Number: 3828