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HomeMy WebLinkAboutChapter 3 - 2030 Transportation ForecastEXHIBIT C ORDINANCE 2012-005 Page 123 of 268 CHAPTER THREE Transportation Forecast 3.1 General Background At the broadest scale, the travel forecast attempts to look at the interaction between land use attractors, population generators, and the linkages between the two. Travel forecasting generally starts by looking at the types of land uses allowed under zoning, the amount and distribution of population and assumptions about how different types of modes (bus, bike, drive alone or carpool, etc.,) people will use. These data are then converted into future vehicle or person trips for a set number of years. Trips are assigned to the roads and highways based on expected travel times. All of this data and information indicate how the transportation network will perform at the end of the planning horizon year and whether there are any resulting deficiencies. In most urbanized areas, the transportation modeling process is done with computer programs that can be highly refined to deal with small geographic areas. Within Deschutes County, both Bend and Redmond have benefited from the use of computer modeling to forecast future road volumes. In those places, the urban areas could be divided into small, multi-block areas known as traffic analysis zones. In simple terms, once the traffic analysis zones or “TAZs” are identified, the computer assigns trips to those zones based on whether an individual zone has more trip attractions (employment, retail, school, etc.) or productions (residential). Finally, the computer identifies the expected traffic volumes on the affected streets. Previously, traffic generators for areas outside of cities utilized two broad approaches. The simpler of the two techniques is using a “trending” alternative to project historical traffic growth trends out towards some future year. In trending, you look as far backward as you’re going to project forward, assuming the percentage growth will remain at its historic rate. In other words, if traffic volumes grew at 3% per year for 1990-2010, then they will grow at 3% per year for 2010-2030. The other, “cumulative analysis” alternative, involves the use of existing traffic, historical growth rates, population, employment and dwelling unit forecasts, and the location of likely future growth, to project traffic. For the Deschutes County Transportation System Plan (TSP) update, the Transportation Planning and Analysis Unit (TPAU) at the Oregon Department of Transportation (ODOT) developed the first transportation-land use model for the rural sections of an Oregon county. This is a hybrid of both approaches which also factors in time spent traveling between attractors and generators when modeling route choices. TPAU worked with County staff on amount of built and vacant lands by zoning, factored in unbuildable lots, looked at present and future development patterns, populations, employment, distance to destinations, and capacity of the road network. The model also contained two simplifying land use assumptions: 1. The future population and employment allocations for Bend, Redmond and Sisters are assumed as given in their models. 2. It is assumed that there will be no increase in employment outside of the urban model areas except in destination resorts. The land use model divided the areas outside urban models into approximately 260 TAZ’s. The model also accounts for the development of recreational and second homes in destination resorts and elsewhere in the study area; these were assumed to be about 13.7 percent of the total future households in the study area. The Deschutes County land use model also makes general allocations of EXHIBIT C ORDINANCE 2012-005 Page 124 of 268 households and employment to Crook and Jefferson counties. The transportation model includes those areas in order to provide better traffic predictions at the Deschutes County boundary. These counties are also important to the allocation of recreational and second home development since Deschutes County is part of the overall Central Oregon market for these types of developments. However, the forecasts are not made at the geographic level of detail of places within Deschutes County as the model focuses on the aggregate picture. Further details on the model are included in Technical Memo #3, 2030 Future Traffic Conditions which is included as Appendix B to the TSP. 3.2 Traffic Forecast The year 2030 traffic projections are used as a planning tool to help test the ability of existing roadways to accommodate 2030 Annual Average Daily Traffic (AADT). The capacity of a roadway depends on a myriad of factors. These include number of lanes, access points per mile, and percent of truck traffic. A higher number of access points means less capacity due to vehicles slowing to turn off of the roadway or entering the roadway and needing to accelerate to the prevailing speed, slowing traffic behind them. Trucks have lower acceleration rates, longer stopping distance, which means they begin to slow sooner on the mainline, and are more affected by hills and curves. The effects of access points and truck traffic are exacerbated on two-lane roadways as trailing vehicles often have no options other than to slow, which creates a ripple effect. ODOT used its land use model to generate 30 different population and employment forecast distributions (scenarios) for 2030. These were then placed into the 2030 Deschutes County travel demand model to look at the effect on various highway, arterial, and collector segments. TPAU recorded the change for each link under each of the scenarios. Most links had no more than a ten (10) percent coefficient of variation, except for a few roads with extremely low Average Daily Traffic (ADT) volumes that were not major parts of the TSP network. (The coefficient of variation measures the range of data points from the mean. The lower the coefficient, the less dispersion there is in the measured variable.) Minor shifts in traffic volumes on roads with low AADT results in significant changes from a percentage standpoint, but not from an absolute numbers perspective.) No matter which of the 30 population and employment scenarios were used, the resulting traffic volumes were essentially the same on the studied links. The resulting forecast volumes can then be used to determine whether the roadway meets the performance standards of either ODOT for State highways or Deschutes County for arterials and collectors. ODOT uses a volume/capacity (V/C) ratio as its measurement while Deschutes County uses time delay know as Level of Service (LOS). The standards apply to both roadway segments and intersections. Where State and County facilities intersect, ODOT’s mobility standard prevails. State highway segments were ranked based on a range of the mobility standards between 0.60 and 0.80 (based on engineering judgment) and the risk of exceeding the applicable mobility standard: • v/c < or = 0.60: Low risk • 0.60 < v/c < 0.80: Medium risk • v/c > or = 0.80: High risk The County’s operational standard for an existing road is LOS D, which is between 5,700 and 9,600 ADT. Roadway segments under the Deschutes County jurisdiction were classified as: EXHIBIT C ORDINANCE 2012-005 Page 125 of 268 • Below LOS D threshold: Low risk • Within LOS D: Medium risk • Above LOS D: High risk. ODOT’s Preliminary Signal Warrant (PSW) was used as a surrogate to evaluate unsignalized intersections. Meeting the AADT warrant only meant the side streets would experience significant delay in entering or crossing the main road. Given the rural location of the majority of these intersections, a traffic signal would not actually be the solution as drivers in high-speed rural areas do not expect them. Due to the sensitivity of the model volumes and the normal fluctuations in volumes, the following warrant thresholds to rank intersection deficiencies were used: • Between 60% and 80% of threshold: Low risk • Between 80% and 100% of threshold: Medium risk • Greater than 100% of threshold: High risk As levels of delay increase on a side street, the concern is drivers will begin to become frustrated or impatient. Drivers may then attempt to pull onto or cross the highway, accepting gaps in traffic on the mainline that are too small to safely make the desired move. Accepting an insufficient gap in high-speed rural traffic can lead to increased crashes. Future Traffic Conditions The 2030 model results show the majority of future congestion will occur on the State highway system. While a highway may have adequate capacity in 2030, the higher volumes could still require more aggressive access management to prevent such crashes as head-ons and those related to turning on/off the highway. (Access management is a method to improve a road’s performance by limiting the number of connections to the road, setting the spacing between connections based on a road’s classification, or restricting turn movements into/out of a roadway.) A few short segments of County roads on the margins of urban areas will experience congestion as will a handful of County-County road intersections which are primarily in the Bend area. Deschutes County Roads Segments Of the arterials and collectors studied in the County, the analysis indicates there are only a few segments that exceed the LOS D standard of 9,600 ADT. The 15 segments are primarily concentrated in the west edge of Redmond (11 segments), the southern and eastern edges of Bend (two segments), and just west of La Pine (two segments). Table 3.2.T1 lists the County road segments and their volumes in 2030. The highest ADT segments in the County are in the Redmond area. These volumes reflect increasing congestion on both US 97 and OR 126 within the City of Redmond. Drivers will divert to Helmholtz Way as an alternate way to get south to 61st Avenue to then access US 97. The 2009 volumes of Helmholtz, which never crack 3,000 ADT even just north of OR 126, will by 2030 have skyrocketed to EXHIBIT C ORDINANCE 2012-005 Page 126 of 268 19,700 ADT just north of the highway, an increase of 557 percent. Similarly, Helmholtz at SW Canal has a 1,965 ADT (2008) which by 2030 becomes 14,200 ADT, an increase of 623 percent. The other Redmond-area County road that will see dramatic growth is Northwest Way. In 2009 Northwest Way at Maple has 2,224 ADT whereas in 2030 the ADT there becomes 10,800, an increase of 386 percent. The County road with the highest ADT in the Bend area is Baker Road between Apache Road and Cinder Butte Road at the southern end of Bend. This segment leads from US 97 into the Deschutes River Woods subdivision. The Baker Road interchange is the southernmost interchange in Bend and thus would serve both residents of Bend and those commuting to/from Sunriver and La Pine. The ADT increases from 6,174 (2009) to 11,100, an increase of 80 percent. Deschutes Market Road in NE Bend serves as a parallel local route to US 97, especially for those with destinations east of 15th Street. The traffic increases from 5,592 (2009) to 10,600, an increase of 90 percent. The model assumes Cooley Road has been extended from 18th Street east to Deschutes Market Road. If this does not happen, then Table 3.2.T1 Deschutes County Roads and 2030 Levels of Service Road From To Ranking AADT LOS Classification Helmholtz Way OR 126 0.25 mi N of OR 126 High 19,700 F Rural Collector Northwest Way Maple Ave 0.5 mi N of Maple Ave High 17,500 F Rural Collector Helmholtz Way 0.25 mi N of Wickiup Ave OR 126 High 17,000 F Rural Collector Canal Boulevard 61st St/ Quarry Ave. Helmholtz Way High 16,500 F Rural Collector Helmholtz Way Coyote Ave. 0.25 mi N of Wickiup Ave High 14,700 E Rural Collector Helmholtz Way Canal Blvd. Elkhorn Ave High 14,200 E Rural Collector Helmholtz Way 0.25 mi N of OR 126 0.25 mi N of Antler Ave High 14,000 E Rural Collector Helmholtz Way 0.25 mi N of Antler Ave Maple Avenue High 12,000 E Rural Collector Cline Falls Hwy Nutcracker Dr. SW ramps of OR 126) High 11,900 E Rural Arterial Helmholtz Way Elkhorn Ave. Coyote Ave High 11,400 E Rural Collector Burgess Rd. Meadow Ln. Huntington Rd High 11,200 E Urban Collector Baker Rd. Apache Rd. Cinder Butte Road High 11,100 E Urban Collector Northwest Way 0.5 miles N of Maple Ave Upas Ave High 10,800 E Rural Collector Deschutes Market Road Hamehook Rd. Margaret Lane High 10,600 E Rural Collector Burgess Rd Day Rd. Meadow Ln High 9,800 E Urban Collector EXHIBIT C ORDINANCE 2012-005 Page 127 of 268 Road From To Ranking AADT LOS Classification Lower Bridge Way 43rd St 31st St Medium 8,800 D Rural Collector S. Century Dr. Spring River Rd. Abbott Road Medium 8,700 D Rural Collector Powell Butte Highway Butler Market Rd. McGrath Road Medium 8,400 D Rural Arterial OB Riley Rd Old Bend Redmond Hwy Destiny Ct Medium 8,000 D Rural Collector Canal Boulevard Elkhorn Ave 39th St Medium 7,800 D Urban Arterial Powell Butte Highway US 20 Neff Rd/Alfalfa Market Rd Medium 7,800 D Rural Arterial Powell Butte Highway McGrath Road Morrill Rd Medium 7,600 D Rural Arterial Baker Rd. US 97 NB ramps Scale House Road Medium 7,100 D Urban Arterial Cline Falls Hwy Cook Ave. Tumalo Road Medium 7,100 D Rural Arterial S. Century Dr. Lazy River Dr. Vandevert Rd Medium 7,100 D Rural Collector Cook Ave OB Riley Rd. Cline Falls Hwy Medium 7,000 D Rural Arterial Old Bend Redmond Hwy. OB Riley Rd. US 20 Medium 6,900 D Rural Collector Knott Rd. Scale House Rd. China Hat Rd Medium 6,800 D Urban Arterial Cline Falls Hwy Coopers Hawk Dr/ Falcon Crest Dr Nutcracker Dr Medium 6,700 D Rural Arterial Powell Butte Highway Morrill Rd County Line Medium 6,700 D Rural Arterial Butler Market Rd . Hamehook Rd Silver Rd. Medium 6,600 D Rural Collector Lower Bridge Way 31st St US 97 Medium 6,600 D Rural Collector Powell Butte Highway Neff Rd/Alfalfa Market Rd Butler Market Rd. Medium 6,400 D Rural Arterial Butler Market Rd. Silver Rd Powell Butte Hwy Medium 6,200 D Rural Collector Deschutes Market Rd. Margaret Lane Dale Rd Medium 6,200 D Rural Collector Burgess Rd. Antler Lane US 97 Medium 6,000 D Urban Collector Northwest Way Coyner Ave. Montgomery Ave Medium 6,000 D Rural Collector Neff Road Glacier Ridge Road Hamby Road Medium 5,800 D Urban Arterial Spring Riv. Rd. Solar Dr. S, Century Dr. Medium 5,700 D Rural Arterial EXHIBIT C ORDINANCE 2012-005 Page 128 of 268 volumes will still increase, just by not as large of an amount. The model also assumes the City’s Juniper Ridge lands that are currently outside the Bend UGB retain their rural zoning. Any UGB amendment and subsequent rezoning for Juniper Ridge would require the City to conduct a traffic study to identify the effects and needed mitigations. In the La Pine area, the only County road that fails is Burgess. The two segments extend from Day Road to Meadow Lane and Meadow Lane to Huntington Road. The Day Road-Meadow Lane segment has an ADT of 3,098 (2008) which becomes 9,800 ADT in 2030, an increase of 216 percent. Meadow Lane to Huntington had 7,922 (2009) which grows by 41 percent to 11,200 ADT. Burgess Road not only leads east to US 97, but also west to the Deschutes River, Wickiup Reservoir, and the Cascade Lakes Highway as Burgess becomes USFS Road #42. Intersections The County sets a standard of LOS D for intersections, which means delays in p.m. peak (4-6 p.m.) on the side street do not exceed 35 seconds on average per vehicle at an unsignalized intersection and less than 55 seconds on average per vehicle at signalized intersections. (Because a traffic signal provides drivers the assurance that ultimately they will able to make their intended maneuver, they will accept more delay than at an unsignalized intersection.) Of the 16 intersections countywide that are classified as needing improvement in 2030, five are county-county connections. Table 3.2.T2 lists the County roads only intersections ranked as high (needing improvement) and medium. The intersections ranked as medium in 2030 do not need improvements, but are at levels of delay sufficient to encourage they be monitored. Table 3.2.T2 Deschutes County Intersections in 2030 County Intersections That Need Improvements Location Ranking Entry AADT Canal Boulevard/SW Helmholtz Way High 16,918 Powell Butte Hwy/Neff-Alfalfa Market High 10,829 Powell Butte Hwy/Butler Market High 10,385 Deschutes Market/Hamehook High 10,208 South Century/Spring River Road High 10,026 County Intersections That Do Not Need Improvements Old Bend Redmond Hwy/O.B. Riley Medium 9,859 Butler Market/Hamehook Medium 8,533 South Century/Vandevert Medium 8,410 Northwest Way/Coyner Medium 7,617 State Highways Segments The analysis indicates there are extensive segments that will exceed ODOT’s mobility standards in 2030. ODOT uses a Volume/Capacity (V/C) ratio for highway segments. The applicable V/C can vary depending on functional classification, Freight Route or Expressway overlay, and whether the highway segment is on rural lands or in an unincorporated community. Table 3.2.T3 lists the state highway segments by V/C. EXHIBIT C ORDINANCE 2012-005 Page 129 of 268 Of the 25 segments listed as high and needing increased capacity, a dozen are on US 97, seven are on US 20, five are on OR 126, and one is on the O’Neil Highway. The US 97 segments are concentrated in the Terrebonne-Redmond area and Sunriver to La Pine. The current STIP has projects already programmed on US 97 for Galloway Avenue to Pershall/O’Neil Highway and the southbound off ramps at Cottonwood. For US 20, the segments are found between Black Butte-Sisters, the Tumalo area, and Bend to the Powell Butte Highway. ODOT is in the late stages of preparing a refinement plan for the long-term solution for US 20 in Tumalo. Table. 3.2.T3 State Highway Segments and 2030 Volume/Capacity State Highway Segments That Fail Highway From To # Directional Lanes AADT V/C Ratio Ranking US 97 11th Ave. (South) Galloway Ave 1 25,100 1.19 High US 97 SB Off Ramp at Cottonwood Road So. Century Dr 1* 23,200 1.19 High US 97 C Ave 0.08 mi N of 11th Ave (South) 1 247,00 1.18 High OR 126 Quail Tree Dr 2 mi east of Quail Tree Dr 1 7,300 1.18 High US 97 Galloway Ave Pershall Way/O'Neil Hwy 1* 24,400 1.15 High US 97 0.08 mi N of 11th Ave (South) 11th Ave (South) 1 23,400 1.10 High US 97 E Ave C Ave 1 21,800 1.08 High US 97 Lower Bridge Way/11th St (North) E Ave 1 22,700 1.07 High OR 126 NW Helmholtz Way 35th St 1 21,000 1.03 High US 20 Bailey Road/7th St 0.76 mi S of OB Riley Road 1 19,200 1.03 High US 20 Hawks Beard Tollgate 1 9,900 1.03 High US 97 So. Century Dr Vandevert Road 1 19,100 1.02 High OR 126 Cline Falls Hwy Ramps NW Helmholtz Way 1 18,900 1.00 High US 20 Tollgate Rail Way 1 11,900 0.98 High US 20 Providence Dr 0.35 mi W of Hamby Road 1 15,900 0.97 High OR 126 Sherman Road 0.73 mi E of Sherman Road 1 16,900 0.97 High US 97 Wimp Way Lower Bridge Way/11th St (North) 1 17,600 0.95 High US 97 Vandevert Road LaPine State Recrea- tion/Fish Hook Rd 1 16,400 0.95 High OR 126 0.73 mi E of Sherman Road County Line (1.30 mi E of Sherman Road) 1 16,600 0.95 High EXHIBIT C ORDINANCE 2012-005 Page 130 of 268 State Highway Segments That Fail Highway From To # Directional Lanes AADT V/C Ratio Ranking O'Neil Hwy Yucca Avenue NE 5th St 1 3,000 0.94 High US 20 Gerking Market Road Bailey Road/7th St 1 15,600 0.9 High US 97 Pine Crest Lane Drafter Road 1 15,100 0.87 High US 97 LaPine State Recreation/Fish Hook Rd Pine Crest Lane 1 14,400 0.86 High US 20 0.35 mi W of Hamby Road Hamby Road 1 12,400 0.83 High US 20 Couch Market Road Gerking Market Road 1 13,800 0.82 High State Highway Segments That Meet Standards US 20 0.67 mi E of Tweed Road Couch Market Road 1 12,500 0.77 Medium US 97 6th Street OR 31 1 12,200 0.76 Medium US 20 Fryrear Road Tweed Road 1 12,400 0.76 Medium US 20 Hamby Road Powell Butte Hwy 1 10,700 0.74 Medium US 20 Cloverdale Road Gist/Cloverdale Road 1 11,700 0.71 Medium US 20 Gist/Cloverdale Rd. Plainview Road 1 10,000 0.70 Medium US 97 Bowery Lane Grandview Drive 2 50,500 0.69 Medium OR 126 Camp Polk Road Cloverdale Road 1 7,700 0.68 Medium US 20 Desperado Trail Cloverdale Road 1 8,700 0.68 Medium US 20 Plainview Road Fryrear Road 1 11,200 0.68 Medium US 97 Deschutes Pleasant Ridge 0.45 mi N Fort Thompson Ln 2 46,300 0.67 Medium US 20 Jeff/Des County Line (0.02 mi N. of McAllister Rd.) McAllister Rd. 1 5,500 0.67 Medium US 20 McAllister Rd. Hawks Beard 1 6,800 0.67 Medium US 97 OR 31 Masten Road 1 9,500 0.65 Medium US 97 Masten Road Klam/Des County Line (0.9 mi South of Jackpine Loop) 1 8,200 0.64 Medium OR 126 Creekside Court Camp Polk Road 1 6,700 0.64 Medium OR 126 101st Street Oasis Drive 1 7,700 0.64 Medium OR 126 Cloverdale Road Quail Tree Drive 1 7,200 0.63 Medium OR 126 2 mi east of Quail Tree Drive Buckhorn/Barr Road 1 7,300 0.63 Medium US 97 0.45 mi north of Ft. Thompson Lane Bowery Lane 2 45,200 0.62 Medium OR 126 Oasis Drive Cline Falls Highway Ramps 1 8,400 0.62 Medium EXHIBIT C ORDINANCE 2012-005 Page 131 of 268 State Highway Segments That Meet Standards US 97 Redmond City Limits Deschutes Pleasant Ridge 2 32,150 0.44 Low US 97 Bend City Limits Baker Road Interchange 2 30,400 0.41 Low *Being improved by current ODOT construction project Regarding the five segments on OR 126, four are split between the west and east side edges of Redmond. State highways are principal arterials that accommodate larger volumes of high-speed rural traffic than are found on County roads. Even if a highway segment is functioning at an acceptable V/C ratio, ODOT may adopt access management measures to lessen the exposure of the traveling public to crashes. Thus, besides adding travel lanes or improving the road’s physical geometry, managing direct access to a state highway can improve a facility’s performance as well as providing a safety benefit. Numerous studies have shown that as the density of access increases, whether public or private, the traffic carrying capacity of the roadway decreases and the vehicular crash rate increases. Additionally, ODOT in the Oregon Highway Plan (OHP) at Policy 3B calls for raised medians when ADT exceeds 28,000 vehicles as a countermeasure to prevent certain types of crashes, primarily head-ons as well as broadsides from turning movements. Several multilane portions of US 97 will exceed that threshold, while remaining at adequate through capacity. Intersections When an ODOT highway and County road intersect ODOT’s V/C ratio is the controlling performance standard. Table 3.2.T4 identifies intersections involving either State highway to State highway intersections or State highway to County road intersections; these are ranked as high (needing improvement) or medium, which means delays are of sufficient length that the intersection should be monitored. Table 3.2.T4 State Highway Intersection Rankings in 2030 Intersections That Will Need Improvement Location Ranking Entry ADT OR 126/Helmholtz Way High 38,992 US 20/Old Bend-Redmond Hwy High 28,639 US 97/O'Neil Hwy-Pershall Way High 28,168 US 20/Cook Ave-O B Riley Rd High 23,474 US 97 / Lower Bridge Way High 23,465 US 97 / Vandevert Rd High 19,772 US 97 SB On & Off Ramp / Baker Rd High 13,476 US 20/Hamby Rd High 12,978 US 20/Powell Butte Hwy High 12,648 US 97/OR 31 High 12,250 US 97 NB Off Ramp/Baker Rd High 11,148 Intersections That Will Need Monitoring, But Not Improvement US 97 / Smith Rock Way Medium 25,437 US 20/ Cloverdale Rd Medium 11,064