Oregon State Shield

Oregon's Highways & Routes

This site is not associated with or sponsored by the Oregon Department of Transportation (ODOT), but is a personal web site based on my interest in the highways of Oregon, my home state. It contains descriptions of modern Oregon Highways and Routes designed for automobile use that are maintained by ODOT and their histories. All the information is to the best of my knowledge, using availble research from ODOT documents and the ODOT website, and my large collection on Oregon Road Maps from the 1920's to today.

If you have any information that can help substantiate or refute any of the information in this site, please write me at e.mike.wiley@gmail.com.

Jump to...
Differnce Between Highways and Routes
Explanation Of Route Symbols
Freeway Exits

Difference Between "Highways" and "Routes"
ODOT Bridge Inventory Marker
An Oregon Bridge Inventory Marker denoting both the route and highway number. This is along the Nehalem Highway #102 and Oregon Route 47.

The Oregon Department of Transportation (ODOT) uses a separate internal "Highway" name and numbers system and a separate public "Route" number system to identify its inventory of roads.

The Highway name and number system dates back to the origination of the Oregon State Highway Commission (OSHC) in 1917. At first, the OSHC marked their highways with a diamond shaped marker identifying the Highway name and number.

After the creation of the US Route system in 1926, there was some concern that the official state Highway number and US Route numbers could be confused. Therefore in 1932, the OSHC created the State Route System, which assigned route number by region of the state using the Eagle and Shield design from the Oregon State Seal. Once that was in place, OSHCremoved all public "Highway" reference from all roads, but kept the system for internal use.

1917 "Highway" Marker
1932 "Route" Marker

Most Oregon Highways have both a Highway number and a Route number that are different as can be seen in the Bridge Inventory Marker shown in the attached picture. However, there were many Secondary Highways that were not assigned a Route Number. Also, a specific Route may transverse multiple Highways. For example, US 26 transverses 7 different Highways as it crosses the state.

In 2002, ODOT began to realign Highway and Route numbers to prevent confusion between the two systems by adding Route Numbers that matched the Highway Numbers on previously unmarked ODOT maintained roads . However, the problem is still not solved as there are many roads that still have a non-matching Highway Number and Route Number, and a small few that remained unmarked or not officially assigned a Route Number.

Definition of a Highway

1932 Gousha Oregon Map
A scan from a 1932 Oregon Road Map printed by Gousha for Shell showing the original Oregon Highway Numbers instead of the Route Number System that was adopted in 1932.

A Highway is a road that is maintained by the ODOT and has a "secret" inventory name and numbers that is not normally posted on the roadside or acknowledge on maps.

Highway Numbers are still used internally by ODOT, and are rarely referenced in public.

In addition, all Mile Posts and Exit Numbers are based on the Highway mileage and not on the Route mileage.

Click on the Highways link either here or in the navigation bar for the details of the Oregon Highway system.

Definition of a Route

Old Route Markers in Downtown Corvallis
Old Oregon and US Route Markers in Downtown Corvallis along the Pacific Highway West #1W (SW 3rd St). Photo take October 1999. As of December 2009, the signs were gone.

A Route is the sign numbers posted on roads and published on maps. ODOT often refers to these as "Signed Routes" or" Map Routes".

Routes are defined as either Interstate, US, or State. The orginal intent of the Route System was for navigation purposes, and not for inventory of ODOT maintained Highways. Therefore, Routes are not just assigned to ODOT maintained roads and may be routed onto county roads or city streets.

ODOT oversees the Route System across all jurisdictions, but local jurisdiction maintain the route number signs on city streets and county roads. Albeit often poorly!

Click on the Routes link either here or in the navigation bar for the details of the Oregon Route system.


Freeway Interchanges

Click on the Freeways link either here or in the navigation bar for the details of the Oregon's Freeways including Exit Numbers and interchange maps.

Explanation Of Route Symbols...
used on this website
I-5 I-205
Current Interstate Routes
I-80N I-505
Former or Canceled Oregon Interstate Routes
US-30 US-395
Current US Routes
US-28 US-630
Former Oregon US Routes or Former Alignment of Current US Routes
OR-22 OR-223
Current Oregon Routes
OR-50 OR-222
Former Oregon State Routes or Former Alignment of Current Oregon Routes
Former Oregon State Highway Marker (Previous to the implementation of Oregon Route Number System in 1932)
I-5 I-505
US-97 US-395
CA-96 CA-139
California Interstate, US, and State Routes
ID-52 ID-200
Idaho State Routes
NV-28 NV-292
Nevada State Routes
WA-14 WA-129
Washington State Routes

Contact the owner at e.mike.wiley@gmail.com for any comments or questions!