Why is planning review required?

Any development on or near a road or other right-of-way owned by the county will require a transportation planning review. The review will identify what effects the project will have on the transportation system and how these effects may be offset.

Developments that are not directly on our right-of-way may also be reviewed if they affect the transportation system.

What does planning review include?

For starters, you’ll show us your project, including the site plan and a narrative description.

We will use this information to determine how many vehicle trips will be created. If it will cause enough new traffic to create a "Transportation Impact", you may be required to offset the traffic impact in your proposal.

We will also review the project to ensure it meets our engineering standards. These standards may include:

  • driveway spacing
  • sidewalk width
  • street lights
  • drainage

How does planning review affect my land use application?

Planning reviews usually result from a land use application, either with the county or one of the cities. We work together with the land use agency to make sure the project can meet their requirements and ours. They will include our requirements in their final decision.

Some requirements that affect the final decision may need to be completed before the decision is reached. These include things like traffic and sight distance studies, or further property information.

Requirements for permits or right-of-way dedications will be included in the final land use decision, and must be completed before a building permit or plat approval can be issued.

What If I just need a building permit?

In some cases, your land use is already permitted and you need us to sign off on your building permit.

In that case, we will review to make sure you already meet our requirements. If so, we’ll sign off on your permit.

If not, we’ll review your application the same way we review land use applications. We may have conditions you will need to meet before we sign off.

What permits will I need?

right-of-way permit will be required for:

  • New or altered driveways entering county roads
  • Structures in the right-of-way, such as signs, posts, fences or non-standard mailboxes
  • Minor physical changes to the right-of-way, such as landscape design or vegetation
  • An existing unpermitted driveway

 A construction permit will be required for anything that makes permanent physical changes to the right-of-way, except for minor changes covered by a right-of-way permit.

Other permits that may be required include sewer connection and utility permits.

Will I have to dedicate part of my property?

A land division or development project sometimes requires the dedication of property for public purposes. As a condition of approval, you may be required to dedicate a portion of your property for one or more of the following:

  • Street improvements
  • Pedestrian or bicycle facilities
  • Drainage
  • Utilities

If there’s a culvert under a county road next to your property, you may be asked to dedicate a slope/drainage easement. This allows the county access to maintain the culvert, preventing future damage to the culvert and your property.

A slope/drainage easement centered on a culvert is typically 25 feet by 25 feet. This may vary depending on the terrain.

The amount and type of dedication will be proportionate to the impact of your development.

What improvements will I have to make to the right-of-way?

Developments with a significant impact may require improvements to the right-of-way. Some examples of these improvements are:

  • Widening the shoulder or pavement
  • Traffic control
  • Landscaping
  • Moving or removing a driveway
  • Bicycle or pedestrian facilities
  • ADA facilities such as curb ramps

We will review your project to determine the impact. We may require additional information, such as the location of existing driveways or roadway conditions in the area of the project. In some cases, a Traffic Impact Analysis may be required.

If improvements are not required right now, you may still have to plan for the future. You may be required to accept a Deed Restriction that requires you and any future owner of the property to share in the cost of future improvements.

What is a Transportation Impact?

A Transportation Impact is defined by the county’s Road Rules. It includes new construction or alterations which increase trips generated by the site:

  • By more than 20%, or
  • By more than 100 trips a day, or
  • By more than ten trips in the peak hour.

A project must generate a minimum of 10 new trips to have a Transportation Impact.

For example, a new single-family home on a vacant lot will generate an average of ten new trips, and therefore has a Transportation Impact. An addition or a replacement house will not generate new trips, so it has no Transportation Impact.

What requirements are there for driveway access?

Driveway placement and design is based on the county’s Design and Construction Manual.

  • The standard for approval is one driveway per property.
  • A property that fronts on two streets is limited to access from the lower classification street.
  • New driveways must meet standards for minimum sight distance.
  • Vegetation trimming or earth movement may be required to achieve this sight distance.
  • A registered traffic engineer may be required to certify sight distance as part of your application.

What if I can’t meet the requirements?

The County Engineer may allow a variance from our standards. This requires written documentation that the variance is in keeping with the intent and purpose of the rules, and that it will not harm the intended function of the county’s road system.

A Road Rules Variance requires a new  application. It has specific time requirements and includes sending out notices to neighboring property owners. The variance procedure, including time frame and noticing requirements, is described in Section 16 of the Multnomah County Road Rules.