Policy 1F: Highway Mobility Policy: It is the policy of the State of Oregon to maintain acceptable and reliable levels of mobility on the state highway system, consistent with the expectations for each facility type, location and functional objectives. Highway mobility targets will be the initial tool to identify deficiencies and consider solutions for vehicular mobility on the state system. Specifically, mobility targets shall be used for:
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- Identifying state highway mobility performance expectations for planning and plan implementation;
- Evaluating the impacts on state highways of amendments to transportation plans, acknowledged comprehensive plans and land use regulations pursuant to the Transportation Planning Rule (OAR 660-12-060); and
- Guiding operations decisions such as managing access and traffic control systems to maintain acceptible highway performance.
Mobility targets for state highways, as established in this policy or as otherwise adopted by the Oregon Transportation Commission as alternative mobility targets, are considered the highway system performance standards in compliance with the TPR (OAR 660-012), including applicability for actions that fall under Section -0060 of the TPR.
Where it is infeasible or impractical to meet the mobility targets, acceptable and reliable levels of mobility for a specific facility, corridor or area will be determined through an efficient, collaborative planning process between ODOT and the local jurisdiction(s) with land use authority. The resulting mobility targets will reflect the balance between relevant objectives related to land use, economic development, social equity, and mobility and safety for all modes of transportation. Alternative mobility targets for the specific facility shall be adopted by the Oregon Transportation Commission as part of the OHP.
Oregon Transportation Commission adoption of alternative mobility targets through system and facility plans should be accompanied by acknowledgement in local policy that state highway improvements to further reduce congestion and improve traffic mobility conditions in the subject area are not expected.
Traffic mobility exemptions in compliance with the TPR do not obligate state highway improvements that further reduce congestion and improve traffic mobility conditions in the subject area.
Strategy 1F.1
Mobility targets are the measure by which the state assesses the existing or forecasted operational conditions of a facility and, as such, are a key component ODOT uses to determine the need for or feasibility of providing highway or other transportation system improvements. These mobility targets are shown in Table 6 and Table 7. For purposes of assessing state highway performance:
- Use the mobility targets below and in Table 6 when initially assessing all state highway sections located outside of the Portland metropolitan area urban growth boundary.
- Use the mobility targets below and in Table 7 when initially assessing all state highway sections located within the Portland metropolitan area urban growth boundary.
- For highways segments where there are no intersections, achieving the volume to capacity ratios in Tables 6 and 7 for either direction of travel on the highway demonstrates that state mobility targets are being met.
- For unsignalized intersections, achieving the volume to capacity ratios in Tables 6 and 7 for the state highway approaches indicates that state mobility targets are being met. In order to maintain safe operation of the intersection, non-state highway approaches are expected to meet or not to exceed the volume to capacity ratios for District/Local Interest Roads in Table 6, except within the Portland metropolitan area UGB where non-state highway approaches are expected to meet or not to exceed a v/c of 0.99.
- At signalized intersections other than interchange ramp terminals (see below), the overall intersection v/c ratio is expected to meet or not to exceed the volume to capacity ratios in Tables 6 and 7. Where Tables 6 and 7 v/c ratios differ by legs of the intersection, the more restrictive of the volume to capacity ratios in the tables shall apply. Where a state highway intersects with a local road or street, the volume to capacity ratio for the state highway shall apply.
- Although an interchange serves both the mainline and the crossroad to which it connects, it is important that the interchange be managed to maintain safe and efficient operation of the mainline through the interchange area. The main objective is to avoid the formation of traffic queues on off-ramps which back up into the portions of the ramps needed for safe deceleration from mainline speeds or onto the mainline itself. This is a significant traffic safety concern. The primary cause of traffic queuing at off-ramps is inadequate capacity at the intersections of the ramps with the crossroad. These intersections are referred to as ramp terminals. In many instances where ramp terminals connect with another state highway, the mobility target for the connecting highway will generally signify that traffic backups onto the mainline can be avoided. However, in some instances where the crossroad is another state highway or a local road, the mobility target will not be a good indicator of possible future queuing problems. Therefore, the better indication is a maximum volume to capacity ratio for the ramp terminals of interchange ramps that is the more restrictive volume to capacity ratio for the crossroad, or 0.85.
- At an interchange within an urban area the mobility target used may be increased to as much as 0.90 v/c, but no higher than the target for the crossroad, if:
- It can be determined, with a probability equal to or greater than 95 percent, that vehicle queues would not extend onto the mainline or into the portion of the ramp needed to safely accommodate deceleration; and
- An adopted Interchange Area Management Plan (IAMP) is present, or through an IAMP adoption process, which must be approved by the Oregon Transportation Commission.
- Because the ramps serve as an area where vehicles accelerate or decelerate to or from mainline speeds, the mobility target for the interchange ramps exclusive of the crossroad terminals is the same as that for the mainline. Metered on-ramps, where entering traffic is managed to maintain efficient operation of the mainline through the interchange area, may allow for greater volume to capacity ratios.
Strategy 1F.2
- Apply mobility targets over at least a 20-year planning horizon when developing state, regional or local transportation system plans, including ODOT's corridor plans.
- When evaluating highway mobility for amendments to transportation system plans, acknowledged comprehensive plans and land use regulations, use the planning horizons in adopted local and regional transportation system plans or a planning horizon of 15 years from the proposed date of amendment adoption, whichever is greater. To determine the effect that an amendment to an acknowledged comprehensive plan or land use regulation has on a state facility, the capacity analysis shall include the forecasted growth of traffic on the state highway due to regional and intercity travel and consistent with levels of planned development according to the applicable acknowledged comprehensive plan over the planning period. Planned development, for the purposes of this policy, means the amount of population and employment growth and associated travel anticipated by the community's acknowledged comprehensive plan over the planning period. The Oregon Transportation Commission encourages communities to consider and adopt land use plan amendments that would reallocate expected population and employment growth to designated community centers as a means to help create conditions that increase the use of transit and bicycles, encourage pedestrian activity, reduce reliance on single occupant vehicle travel and minimize local traffic on state highways.
Strategy 1F.3
In the development of transportation system plans or ODOT facility plans, where it is infeasible or impractical to meet the mobility targets in Table 6 or Table 7, or those otherwise approved by the Oregon Transportation Commission, ODOT and local jurisdictions may explore different target levels, methodologies and measures for assessing mobility and consider adopting alternative mobility targets for the facility. While v/c remains the initial methodology to measure system performance, measures other than those based on v/c may be developed through a multi-modal transportation system planning process that seeks to balance overall transportation system efficiency with multiple objectives of the area being addressed.
Examples of where state mobility targets may not match local expectations for a specific facility or may not reflect the surrounding land use, environmental or financial conditions include:
- Metropolitan areas or portions thereof where mobility expectations cannot be achieved and where they are in conflict with an adopted integrated land use and transportation plan for promoting compact development, reducing the use of automobiles and increasing the use of other modes of transportation, promoting efficient use of transportation infrastructure, improving air quality, and supporting greenhouse gas reduction objectives;
- When financial considerations or limitations preclude the opportunity to provide a planned system improvement within the planning horizon;
- When other locally adopted policies must be balanced with vehicular mobility and it can be shown that these policies are consistent with the broader goals and objectives of OTP and OHP policy;
- Facilities with high seasonal traffic;
- Special Transportation Areas; and
- Areas where severe environmental or land use constraints16 make infeasible or impractical the transportation improvements necessary to accommodate planned land uses or to accommodate comprehensive plan changes that carry out the Land Use and Transportation Policy (1B).
Any proposed mobility target that deviates from the mobility targets in Table 6 or Table 7, or those otherwise approved by the Commission, shall be clear and objective and shall provide standardized procedures to ensure consistent application of the selected measure. The alternative mobility target(s) shall be adopted by the Oregon Transportation Commission as an amendment to the OHP. Consideration of alternative mobility targets shall be coordinated with other local jurisdictions in the affected corridor, consistent with OTC Policy 11- Public Involvement.
The Transportation Commission has sole authority to adopt mobility targets for state highways. It will be necessary for affected local jurisdictions to agree to the alternative mobility target for the state highway facility as part of a local transportation system plan and regional plan (MPO) as applicable. Findings shall demonstrate why the particular mobility target is necessary, including the finding that it is infeasible or impractical to meet the mobility targets in Table 6 or Table 7, or those otherwise approved by the Commission.
If alternative targets are needed but cannot be established through the system planning process prior to adoption of a new or updated transportation system plan, they should be identified as necessary and committed to as a future refinement plan work item with an associated timeframe for completion and adoption. In this case, the mobility targets in Table 6 or Table 7, or those otherwise approved by the Commission, shall continue to apply until the alternative mobility targets are formally adopted by the Oregon Transportation Commission.
Modifications to the mobility targets could include changing the hour measured from the 30th highest hour, using multiple hour measures, or considering weekday or seasonal adjustments. Development of corridor or area mobility targets is also allowed. ODOT's policy is to utilize a v/c based target and methodology as the initial measure, as this will standardize and simplify implementation issues throughout the state. Where v/c-based approaches may not meet all needs and objectives, developing alternative mobility targets using non v-c-based measures, may also be pursued.
In support of establishing the alternative mobility target, the plan shall include feasible actions for:
- Providing a network of local streets, collectors and arterials to relieve traffic demand on state highways and to provide convenient pedestrian and bicycle ways;
- Managing access and traffic operations to minimize traffic accidents, avoid traffic backups on ramps, accommodate freight vehicles and make the most efficient use of existing and planned highway capacity;
- Managing traffic demand and incorporating transportation system management tools and information, where feasible, to manage peak hour traffic loads on state highways;
- Providing and enhancing multiple modes of transportation; and
- Managing land use to limit vehicular demand on state highways consistent with Policy 1B (Land Use and Transportation Policy).
The plan shall include a financially feasible implementation program and shall demonstrate that the proposed mobility target(s) are consistent with and support locally adopted land use, economic development, and multimodal transportation policy and objectives. In addition, the plan shall demonstrate strong local commitment, through adopted policy and implementation strategies, to carry out the identified improvements and other actions.
ODOT understands that in certain areas of the state, achieving the established mobility targets will be difficult and that regional and local policies must be balanced with transportation system performance. ODOT is committed to work with MPOs and local jurisdictions on system-level analysis of alternative mobility targets and to participate in public policy-level discussions where balancing mobility and other regional and community objectives can be adequately addressed.
In developing and applying alternative mobility targets and methodologies for facilities throughout the state, ODOT will consider tools and methods that have been successfully used previously for a particular facility and/or within a specific metropolitan area or region. Specific mobility targets may vary from one community or area to another depending on local circumstances. It is the objective of this policy to maintain consistency in the selection and application of analysis and implementation methodologies over time as they are applied to a specific facility or to a system of related facilities within a defined community or region.
ODOT will provide guidance documents and will work with local jurisdictions and others to apply best practices that streamline development of alternative mobility targets.
Strategy 1F.4
Alternative mobility targets may also be developed for facilities where an investment has been, or is planned to be, made that provide significantly more capacity than is needed to serve the forecasted traffic demand based on the existing adopted local comprehensive plan. In these situations, it is possible to preserve that excess capacity for traffic growth beyond the established planning horizon or traffic growth resulting from local legislative plan amendments or plan amendments associated with OAR 731-01.
Strategy 1F.5
For purposes of evaluating amendments to transportation system plans, acknowledged comprehensive plans and land use regulations subject to OAR 660-12-0060, in situations where the volume to capacity ratio or alternative mobility target for a highway segment, intersection or interchange is currently above the mobility targets in Table 6 or Table 7 or those otherwise approved by the Oregon Transportation Commission, or is projected to be above the mobility targets at the planning horizon, and transportation improvements are not planned within the planning horizon to bring performance to the established target, the mobility target is to avoid further degradation. If an amendment subject to OAR 660-012-0060 increases the volume to capacity ratio further, or degrades the performance of a facility so that it does not meet an adopted mobility target at the planning horizon, it will significantly affect the facility unless it falls within the thresholds listed below for a small increase in traffic.
In addition to the capacity increasing improvements that may be required to mitigate impacts, other performance improving actions to consider include, but are not limited to:
- System connectivity improvements for vehicles, bicycles and pedestrians.
- Transportation demand management (TDM) methods to reduce the need for additional capacity.
- Multi-modal (bicycle, pedestrian, transit) opportunities to reduce vehicle demand.
- Operational improvements to maximize use of the existing system.
- Land use techniques such as trip caps / budgets to manage trip generation.
In applying ?avoid further degradation? for state highway facilities already operating above the mobility targets in Table 6 or Table 7 or those otherwise approved by the Oregon Transportation Commission, or facilities projected to be above the mobility targets at the planning horizon, a small increase in traffic does not cause ?further degradation? of the facility.
The threshold for a small increase in traffic between the existing plan and the proposed amendment is defined in terms of the increase in total average daily trip volumes as follows:
- Any proposed amendment that does not increase the average daily trips by more than 400.
- Any proposed amendment that increases the average daily trips by more than 400 but less than 1001 for state facilities where:
- The annual average daily traffic is less than 5,000 for a two-lane highway
- The annual average daily traffic is less than 15,000 for a three-lane highway
- The annual average daily traffic is less than 10,000 for a four-lane highway
- The annual average daily traffic is less than 25,000 for a five-lane highway
- If the increase in traffic between the existing plan and the proposed amendment is more than 1000 average daily trips, then it is not considered a small increase in traffic and the amendment causes further degradation of the facility and would be subject to existing processes for resolution.
In applying OHP mobility targets to analyze mitigation, ODOT recognizes that there are many variables and levels of uncertainty in calculating volume-to-capacity ratios, particularly over a specified planning horizon. After negotiating reasonable levels of mitigation for actions required under OAR 660-012-0060, ODOT considers calculated values for v/c ratios that are within 0.03 of the adopted target in the OHP to be considered in compliance with the target. The adopted mobility target still applies for determining significant affect under OAR 660-012-0060.
Strategy 1F.6
When making recommendations to local governments about development permit applications and potential actions for mitigation related to local development proposals and criteria consider and balance the following:
- OHP mobility targets;
- Community livability objectives;
- State and local economic development objectives
- Safety for all modes of travel; and
- Opportunities to meet mobility needs for all modes of travel.
Encourage local jurisdictions to consider OHP mobility targets when preparing local development ordinances and approval criteria to evaluate proposed development applications that do not trigger Section 660-012-0060 of the TPR.
Strategy 1F.7
Consider OHP mobility targets as guidance to ODOT's highway access management program. Balance economic development objectives of properties abutting state highways with transportation safety and access management objectives of state highways in a manner consistent with local transportation system plans and the land uses permitted in acknowledged local comprehensive plans. When evaluating OHP mobility targets in access management decisions for unsignalized intersections consider the following:
- The highest priority for the use of OHP mobility targets in guiding access management practices is to address the state highway through traffic movements and the movements exiting the state highway facility.
- When evaluating traffic movements from an approach entering or crossing a state highway, the priority is to consider the safety of the movements. While a v/c ratio for a specific movement greater than 1.0 is an indication of a capacity problem, it does not necessarily mean the traffic movement is unsafe. Apply engineering practices and disciplines in the analysis and design of highway approaches to ensure traffic movements meet safety objectives for the program.
Private approaches at signalized intersections will be treated as all other signalized intersections under OHP Action 1F.1.
Strategy 1F.8
Consider OHP mobility targets when implementing operational improvements such as traffic signals and ITS improvements on the state highway system. The OHP mobility targets are meant to be used as a guide to compare the relative benefits of potential operational solutions rather than as a firm standard to be met. The main goal of operational projects is to improve system performance - which may include mobility, safety or other factors - from current or projected conditions.
Strategy 1F.9
Enhance coordination and consistency between planning and project design decisions whenever possible. Ensure that project development processes and design decisions take into account statewide mobility and economic objectives, including design standards, while balancing community mobility, livability and economic development objectives and expectations. Consider practical design principles that take a systematic approach to transportation solutions in planning and project development processes. Practical design principles strive to deliver the broadest benefits to the transportation system possible within expected resources.
Strategy 1F.10
The 2011 amendments to OHP Policy 1F and associated amendments to the TPR may lead to impacts in traffic mobility in specific corridors and on the overall state highway system that cannot be fully anticipated. ODOT shall evaluate the effectiveness of the policy in meeting broad objectives, the impacts on transportation system performance and safety, and any unintended consequences resulting from implementation within three years of adoption of this Action. Following the initial review, the mobility targets and associated policies will be reviewed periodically based on a schedule determined by the Oregon Transportation Commission.