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HomeMy WebLinkAboutTile Flat Analysis Summary_6-10-2025 Draft Page | 1 MEMORANDUM DATE: June 10, 2025 TO: River Terrace 2.0 Project Management Team FROM: Adrian Witte, Toole Design and Kevin Chewuk, DKS Associates SUBJECT: River Terrace 2.0 Community Plan Tile Flat Extension Scenarios Evaluation – Summary #24434-000 This memorandum summarizes the multimodal transportation analysis methodology and findings for the evaluation of Tile Flat extension scenarios as part of the River Terrace 2.0 Community Plan. Included are the objectives of the study, a summary of the primary street network and Tile Flat extension scenarios, the performance metrics used to compare scenarios, and the results of the analysis, which will be used by staff to identify a recommendation for decision makers moving forward. STUDY OBJECTIVES The objective of the study is to compare holistic benefits, impacts, and costs of the different primary street network scenarios and to understand and quantify if there are additional benefits to extending Tile Flat Road or Mountainside Way beyond providing the base network identified in the River Terrace 2.0 Concept Plan. TILE FLAT EXTENSION SCENARIOS The team identified four primary street network scenarios to be evaluated within the River Terrace 2.0 Community Planning process – two of these extend Mountainside Way without a connection to Tile Flat Road and two include an extension of Tile Flat Road to meet Mountainside Way. All scenarios provide a primary north to south collector route along Mountainside Way connecting from Scholls Ferry Road and running west of and eventually connecting to Roy Rogers Road at the Bull Mountain Road intersection and/or areas further south. This scenario is identified as Scenario 1. The conceptual alignments of the primary streets for each of the four scenarios are shown on Figure 1 through Figure 4, although the alignments could be shifted to better serve the surrounding neighborhood or provide other system benefits (e.g., to reduce costs, lessen impacts to sensitive lands, provide better connectivity, etc.). The Tile Flat extension scenarios include: Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 2 • Scenario 1: Includes the Mountainside Way extension from Scholls Ferry Road to the Roy Rogers Road / Bull Mountain Road intersection (Segment A) and is shown in red on Figure 1. • Scenario 2: Includes Segment A, plus the Tile Flat Road extension from Scholls Ferry Road to the Mountainside Way extension (Segment B) and is shown in green on Figure 2. • Scenario 3: Includes Segment A, plus the extension of Mountainside Way from Bull Mountain Road to connect with Roy Rogers Road somewhere at or between the Perth Road or Woodhue Street intersections (Segment C) and shown in blue on Figure 3. • Scenario 4: Includes Segments A, B and C and is shown in purple on Figure 4. Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 3 FIGURE 1 : TILE FLAT EXTENSION SCENARIO 1. SW Lasich Ln SW Bull Mtn Rd SW Beef Bend Rd SW R o y R o g e r s R d SW Scholls Ferry Rd SW Jean Louise Rd SW Woodhue St SW R i v e r T e r r a c e B l v d SW V a n d e r m o s t R d SW Clementine St A A Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 4 FIGURE 2 : TILE FLAT EXTENSION SCENARIO 2. SW Lasich Ln SW Bull Mtn Rd SW Beef Bend Rd SW R o y R o g e r s R d SW Scholls Ferry Rd SW Jean Louise Rd SW Woodhue St SW R i v e r T e r r a c e B l v d SW V a n d e r m o s t R d SW Clementine St A A SW Tile Flat Rd B B Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 5 FIGURE 3 : TILE FLAT EXTENSION SCENARIO 3. SW Lasich Ln SW Bull Mtn Rd SW Beef Bend Rd SW R o y R o g e r s R d SW Scholls Ferry Rd SW Jean Louise Rd SW Woodhue St SW R i v e r T e r r a c e B l v d SW V a n d e r m o s t R d SW Clementine St A A SW M o u n t a i n s i d e W a y C Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 6 FIGURE 4 : TILE FLAT EXTENSION SCENARIO 4. SW Lasich Ln SW Bull Mtn Rd SW Beef Bend Rd SW R o y R o g e r s R d SW Scholls Ferry Rd SW Jean Louise Rd SW Woodhue St SW R i v e r T e r r a c e B l v d SW Va n d e r m o s t R d SW Clementine St A A SW M o u n t a i n s i d e W a y C SW Tile Flat Rd B B Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 7 PERFORMANCE METRICS The Tile Flat extension scenarios were compared using the performance metrics shown below. These include a mix of quantitative and qualitative considerations. Wherever possible, findings were communicated in terms of resident and traveler experiences, with a focus on identifying meaningful differences between scenarios. The complete results of the analysis are included in the full evaluation memorandum attached to this summary. 1. Vehicular Network A. Vehicle Miles Traveled (VMT) B. Quantity of Travel C. Intersection Capacity D. Travel Time 2. Multimodal Network A. Bicycle Level of Traffic Stress (BLTS) B. Pedestrian Level of Traffic Stress C. Connectivity D. Vulnerable Road User Safety E. Future Transit Service 3. Environmental / Livability A. GHG and Emissions B. Natural Resource Impacts C. Livability Impacts of Regional Vehicle Trips 4. Development Feasibility A. Support to Commercial Areas B. Land Use and Development Feasibility C. Order-of-Magnitude Infrastructure Costs D. Timing, Phasing, and Project Cost E. Fire, Life, Safety 5. Equity A. Equitable Benefits Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 8 EVALUATION SUMMARY The primary street network scenarios were compared in how they performed against one another for the metrics listed above. A summary of the results is included in Table 1. TABLE 1 : SUMMARY OF EVALUATION RESULTS SCENARIO 1 SCENARIO 2 SCENARIO 3 SCENARIO 4 1. VEHICULAR NETWORK A1. Vehicle Miles Traveled on the Arterial Street Network Total VMT change from no-build: - 0.5% Total VMT change from no-build: +1.0% Total VMT change from no-build: - 0.4% Total VMT change from no-build: - 0.3% A2. Vehicle Miles Traveled on the Primary and Secondary Street Network Share of Total VMT for RT 2.0 Trips: 92% Share of Total VMT for RT 2.0 Trips: 47% Share of Total VMT for RT 2.0 Trips: 62% Share of Total VMT for RT 2.0 Trips: 48% B. Quantity of Travel Lowest overall ADT volumes ADT volumes are higher along Mountainside Way compared to Scenarios 1 and 3 Slighly higher ADT volumes along Mountainside Way compared to Scenario 1, but otherwise similiar Highest overall ADT volumes C. Intersection Capacity This scenario results in the highest v/c ratios on Scholls Ferry and competitive or lower v/c ratios along Roy Rogers. This scenario results in improved operations along Scholls Ferry with some degradation of operations at the Roy Rogers & Bull Mountain intersection. This scenario results in similar operations on Scholls Ferry to Scenario 1, improved operations along parts of Roy Rogers, and some degradation of operations at the Roy Rogers & Perth intersection. This scenario results in improved operations along Scholls Ferry with some degradation of operations at the Roy Rogers intersections with Bull Mountain and Perth. D. Travel Time 6.91 minutes (-11 seconds from no-build) 6.88 minutes (-13 seconds from no-build) 7.07 minutes (-2 seconds from no-build) 6.63 minutes (-28 seconds from no-build) 2. MULTIMODAL NETWORK A. Bicycle Level of Traffic Stress – Relative Investment Needed to Meet BLTS 1 Lowest investment to achieve BLTS 1 Achieves BLTS 1 with some costs for median crossings at all locations Achieves BLTS 1 with some costs for additional median crossings Achieves BLTS 1 with some costs for median crossings at all locations Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 9 SCENARIO 1 SCENARIO 2 SCENARIO 3 SCENARIO 4 B. Pedestrian Level of Traffic Stress – Relative Investment Needed to Meet PLTS 1 Lowest investment to achieve PLTS 1 Achieves PLTS 1 with some costs for additional median crossings Achieves PLTS 1 with some costs for additional median crossings Achieves PLTS 1 with some costs for additional median crossings C. Connectivity Provides sufficient connectivity for development and good walkshed coverage Provides additional local and regional connectivity and walkshed coverage Provides additional local connectivity and walkshed coverage Provides the most local and regional connectivity and walkshed coverage D. Vulnerable Road User Safety Lowest VRU crash exposure VRU crash exposure is somewhat higher than Scenario 1 VRU crash exposure is somewhat higher than Scenario 1 VRU crash exposure is considerably higher than Scenario 1 E. Future Transit Service Primary route provides good coverage and lowest traffic volumes minimize delays Alternative routes available but may reduce Coverage. Traffic volumes may result in some transit delays Alternative routes could provide additional residential coverage but reduce commercial exposure. Alternative routes could reduce commercial exposure. Traffic volumes may result in transit delays 3. ENVIRONMENTAL / LIVABILITY A. GHG & Emissions Lowest potential for emissions in RT 2.0 Emissions potential is considerably higher than Scenario 1 Emissions potential is somewhat higher than Scenario 1 Emissions potential is considerably higher than Scenario 1 B. Natural Resource Impacts Fewest stream crossings, some impact to trees, lowest impervious surface Additional stream crossing, some impact to trees, potential wetlands impact, increased impervious surface Additional stream crossing, some impact to trees, increased impervious surface Two additional stream crossings, some impact to trees, potential wetlands impact, highest impervious surface C. Livability Impacts of Regional Vehicle Trips Lowest cut- through traffic and a small proportion of street volume Cut-through traffic is considerably higher than Scenario 1 and high proportion of street volume Some increase in cut-through traffic compared to Scenario 1 and relatively small portion of street volume Cut-through traffic is considerably higher than Scenario 1 and high proportion of street volume 4. DEVELOPMENT FEASIBILITY A. Support to Commercial Areas Provides highest overall pass-by Provides highest pass-by traffic for Provides best performance for SFMW but lower Provides best performance for RRBM but lower Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 10 SCENARIO 1 SCENARIO 2 SCENARIO 3 SCENARIO 4 traffic but lower walkshed coverage RRBM and good walkshed coverage pass-by traffic for RRBM pass-by traffic for SFMW B. Land Use & Development Feasibility Costs can be supported by development, potential impact on development yield on Vandermost Higher costs may have implications on funding strategy. Some additional dedication needs Higher costs may have implications on funding strategy. Some additional dedication needs and potential impacts on development yield on Vandermost Highest costs may have significant implications on funding strategy. Some additional dedication needs C. Order of Magnitude Infrastructure Costs Lowest cost and no need for CIP, County, or City funding sources Approximately double the cost of Scenario 1 and may need CIP, County, or City funding sources Higher cost compared to Scenario 1 and may need CIP, County, or City funding sources Approaching triple the cost of Scenario 1 and may need CIP, County, or City funding sources D. Timing, Phasing, and Project Cost Phasing can be structured to delay costs Additional stream crossing may bring forward costs Additional stream crossing may bring forward costs Two additional stream crossings may bring forward costs E. Fire, Life, and Safety Meets fire, life safety needs with some impacts on development on Vandermost Meets fire, life safety needs with multiple accesses and response directions. Higher traffic volumes may impact emergency response time Meets fire, life safety needs with some impacts on development on Vandermost Meets fire, life safety needs with multiple accesses and response directions. Higher traffic volumes may impact emergency response time 5. EQUITY A. Equitable Impacts Lowest exposure to emissions, noise, and crash risk but some impacts from climate resilience Higher exposure to emission, noise, and crash risk, impacts to housing affordability and climate resilience Higher exposure to emission, noise, and crash risk, impacts to housing affordability and climate resilience. Increased connectivity Highest exposure to emission, noise, and crash risk and impacts to housing affordability and climate resilience. Increased connectivity Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 11 Each scenario and where it performs well and not so well is summarized below. SCENARIO 1 Where does it perform well? • This scenario results in the lowest internal traffic volumes which provides benefits in terms of reducing exposure to crash risk, noise, and emissions for future residents of RT 2.0 West. This has the potential to provide the greatest benefit to residents and vulnerable population groups living in RT 2.0 West. • By limiting the number of stream crossings and the scale of streets and intersections, this scenario is the least impactful on natural systems. • Traffic exposure for commercial areas is highest under this scenario. • It is the lowest cost scenario, which can help reduce development costs and make housing more affordable. It will also allow development to be phased in a way that allows major infrastructure to be brought online once a critical mass of development triggers the need for these improvements. Where does it not perform so well? • This scenario provides the least benefit to arterial street operations and travel time reductions for regional travelers. However, arterial street operations and travel time differences are not significantly different compared to other scenarios. • Not extending Tile Flat Road and Mountainside Way reduces regional connectivity to destinations northwest of River Terrace and local connectivity to RT 1.0, RT 2.0 South, and Kingston Terrace respectively. The area on SW Vandermost Road will rely on SW Scholls Ferry Road to access other parts of RT2.0. However, development potential is expected to be limited in this area and can address fire, life, and safety needs. SCENARIO 2 Where does it perform well? • This scenario increases connectivity and access by extending Tile Flat Road to meet Mountainside Way. This increases access to regional destinations northwest of River Terrace 2.0, provides some incremental benefits to traffic operations on Scholls Ferry Road, marginally increases the amount of development in walking distance to key destinations, provides improved access to the area on Vandermost Road, and provides emergency access from a third primary direction. Where does it not perform so well? • This scenario draws traffic from Scholls Ferry Road resulting in increased internal traffic volumes, changes in traffic patterns that degrade intersection operations at the Roy Rogers & Bull Mountain Road intersection, and increased VMT while providing no significant reduction in travel time for people driving through the area in comparison with Scenario 1. The increase in internal traffic volumes and a new intersection with Mountainside Way will increase crash exposure, noise, emissions, and livability impacts on local residents. Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 12 • Not extending Mountainside Way south of Bull Mountain (compared to Scenarios 3 and 4) reduces local connectivity to RT 1.0, RT 2.0 South, and Kingston Terrace and route options for future transit service. • This scenario requires an additional stream crossing and additional street and intersection improvements. This increases the impact on natural systems. It will also increase infrastructure costs, which could bring forward the need to construct major infrastructure such as stream crossings before development can support them which would need to be funded outside of the RT 2.0 development schedule. SCENARIO 3 Where does it perform well? • This scenario increases connectivity and access by extending Mountainside Way to meet Roy Rogers Road at the Perth Road intersection. This increases local access to RT 1.0, RT 2.0 South, and Kingston Terrace and provides more route options for future transit service. It also marginally increases the amount of development in walking distance to key destinations. Where does it not perform so well? • This scenario draws traffic from Roy Rogers Road which provides some slight benefit to traffic operations on Roy Rogers Road, but results in increased internal traffic volumes, increased VMT, and overall increased travel time for people driving through the area. The increase in internal traffic volumes is not as significant as Scenarios 2 and 4, but will still see some increase in crash exposure, noise, emissions, and livability impacts on local residents. • Not extending SW Tile Flat Road (compared to Scenarios B and D) reduces regional connectivity to destinations northwest of River Terrace. The area on SW Vandermost Road will rely on SW Scholls Ferry Road to access other parts of RT2.0. However, development potential is limited in this area and can address fire, life, and safety needs. • This scenario requires an additional stream crossing and additional street and intersection improvements. This increases its impact on natural systems. It will also increase infrastructure costs, which could impact housing affordability and may bring forward the need to construct major infrastructure such as stream crossings before development can support them which would need to be funded outside of the RT 2.0 development schedule. SCENARIO 4 Where does it perform well? • This scenario maximizes connectivity and access by extending Tile Flat Road and Mountainside Way. The Tile Flat Road extension increases access to regional destinations northwest of River Terrace, provides improved access to the area on Vandermost Road, and provides emergency access from a third primary direction. The Mountainside Way extension increases local access to RT 1.0, RT 2.0 South, and Kingston Terrace and provides more route options for future transit service. Both extensions increase the amount of development in walking distance to key destinations. • This scenario draws traffic from Scholls Ferry Road and Roy Rogers Road which provides some incremental benefit to traffic operations on the arterial network and a very slight (<30 seconds) travel Evaluation of Tile Flat Extension Scenarios – Summary June 2025 Page | 13 time savings for regional travelers. However, capacity freed up on the arterial street network is expected to be filled by regional trips diverting from other congested corridors, resulting in a negligible change in VMT for this scenario along Roy Rogers Road and Scholls Ferry Road compared to no-build. Where does it not perform so well? • This scenario draws traffic from Scholls Ferry Road and Roy Rogers Road and results in the highest increase in internal traffic volumes, causing significant increases in crash exposure, noise, emissions, and livability impacts on local residents. • This scenario requires two additional stream crossings and the highest number of street and intersection improvements. This significantly increases the impact on natural systems. It will also significantly increase infrastructure costs, which could impact housing affordability and may bring forward the need to construct major infrastructure such as stream crossings before development can support them which would need to be funded outside of the RT 2.0 development schedule. RECOMMENDED SCENARIO The project team recommends that Scenario 1 be developed with a stub provided to the south edge of the development to allow for the future extension of Mountainside Way if the area south of RT 2.0 West (that is currently undesignated area outside the UGB) is ever annexed into the City of Tigard and developed. Scenario 1 outperforms the other scenarios in terms of cost, reduced impact on development and natural resources, and has the lowest potential impact to RT 2.0 residents. There are some connectivity benefits to areas of RT 1.0, RT 2.0 South, and Kingston Terrace if SW Mountainside Way was extended further south in the future. The scenarios that extend SW Tile Flat Road to connect to SW Mountainside Way do provide additional connectivity for regional travelers to areas northwest of RT 2.0. However, they provide limited arterial street operational benefits and do not seem worth the significant added cost and impacts to natural systems, development phasing, and local residents that will live in RT 2.0.