Road and Bridge

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Contact Information
(208) 529-1290

Ken Ray - Road Manager

Office Hours: Monday - Thursday 7:00am - 5:30pm
Phone: (208) 529-1290
Fax: (208) 529-1295

Office Address (MAP)
2700 Manwill Road
Idaho Falls, ID

Mailing Address
605 N Capital Ave
Idaho Falls, ID 83402

Quick Links

Road Construction Drawings

The Road and Bridge Division maintains more than 1000 miles of county roadways including 103 State-inspected bridges (20' span or greater), hundreds of local bridges(less than 20' span) and thousands of drainage structures and road signs. The Division also works closely with the U.S. Forest Service to maintain nearly 100 miles of roads within their boundaries.


Bonneville County has had single lane roundabouts at different intersections for several years and has installed new 2 lane versions at the Lincoln Road/25th East intersection and Lincoln Road/Ammon Road intersection. General information on driving through a 2 lane roundabout is available with the following video links are also available:

Washington State DOT
Lacey City
Peel Roundabouts

Snow Removal Policy


The Board of County Commissioners has set the following road priorities for snow removal:

First: High volume arterial roads; sanding of high volume intersections, railroad crossings, school approaches, sharp curves, steep grades.
Second: High to medium traveled collector roads including school bus routes.
Third: Low volume local roads, primarily subdivision roads, secondary roads and areas for recreation.

The standard snow removal process includes the following:
  - Monitor weather forecasts to anticipate the potential size and duration of expected storms.
   - Apply salt brine solution to road surface 12-24 hours prior to storm event.
   - During severe winter storms with high winds and/or minimal visibility, no equipment is mobilized until conditions improve to the point that snow removal operations don’t endanger the operators, equipment or the public.
   - Sanding operations commence when safe for the road crews to mobilize.
   - Remove as much snow and ice as possible from the road surface. This may take several days and may also include “widening” the roadway (pushing the snow to the limits of the right-of-way).

Road & Bridge WILL NOT remove snow from private roads and driveways including those portions in the public right-of-way.

ENCROACHMENTS - Roadway encroachments present a serious hazard for equipment operators. Encroachments can include landscaping, mailboxes, parked vehicles or piled snow from a residence or business. Road & Bridge will not assume any responsibility for damage to landscaping located in the right-of-way or mailboxes located too close to the roadway. Property owners who create obstructions/encroachments in the public right-of-way can be issued a misdemeanor citation from the Sheriff’s office and could be liable for any injuries or damages occurring because of the obstruction.

FENCES - Right-of-way fences will be repaired ONLY if the damage is from Road & Bridge equipment actually hitting the fence. The County is not responsible for damage done while removing the snow from the road.

Traffic Signs

Road & Bridge maintains thousands of traffic signs and other traffic control devices including signal lights, school flasher warnings and roadway pavement markings. All forms of traffic control in Bonneville County follow the national guidelines outlined in the Manual of Uniform Traffic Control Devices (MUTCD). Please report any damaged or missing traffic sign to the Road & Bridge at 529-1290.

Stop Signs – Damaged or missing stop signs should be reported immediately to the 911 dispatcher or to Road & Bridge at 529-1290 during business hours (Monday – Thursday 7:00 am – 5:30 pm). Missing or damaged STOP and YIELD signs are considered urgent and considered a top safety priority.

Public Street Name Signs – Road & Bridge is responsible for maintenance of street name signs on County (public) roads. Street signs on public roads are white lettering on a green background. Please report damaged or missing street signs to the Road & Bridge at 529-1290.

Private Street Name Signs - Road & Bridge is NOT responsible for maintenance of private street name signs. Street signs on private roads are white lettering on a blue background.

Slow Children at Play - An often-heard neighborhood request concerns the posting of warning signs with "SLOW CHILDREN AT PLAY” or other similar messages. These requests stem from parents concern for the safety of their children in the street or near their homes. Unfortunately, these requests are based upon a widespread false belief that all traffic signs provide protection.

"SLOW CHILDREN AT PLAY” signs create a false sense of security for parents and children. Parents think these signs provide an added measure of protection - but motorists often pay little attention to them. Playing in the street is unsafe and "SLOW CHILDREN AT PLAY” signs are a direct and open suggestion to small children the street is an acceptable place to play.  It is important for parents to teach their children about the dangers of playing near or in the street.

Studies made in areas around the nation where such signs were widely posted in residential areas show no evidence of having reduced pedestrian crashes, vehicle speed or legal liability.   Since there are children on virtually every residential street in Bonneville County, signs would have to be posted on every street. Otherwise, it would suggest there are no children in areas where signs are not posted.

Because of these serious considerations, Idaho State law does not recognize, and Federal Standards discourage, the use of "SLOW CHILDREN AT PLAY SIGNS". Bonneville County’s policy does not provide for the installation of these signs.  Specific warnings for schools, playgrounds, parks, and other recreational facilities are available for use where clearly justified.

Dust Control

Soil stabilization and dust control measures have been a part of regular maintenance of gravel county roads for years. Originally, different materials were placed on roads with steep slopes to help prevent washboarding and the loss of gravel material. The same chemicals used for soil stablization also helped to reduce dust along gravel roads and over time dust control became the primary use of the chemicals.

The cost and requests to provide dust control countywide have increased to the point where the County now has a policy putting the financial cost on the property owners making the request. Resolution 17-04 authorized the dust control policy and the form requesting dust control can be found at Dust Control Application 2024.

Transportation Planning

Traffic Counts - The Road & Bridge is constantly monitoring the change in traffic volumes and patterns in order to plan a better transportation system that accommodates the future needs of the public. Traffic counters are placed on various County roads at different times of the year to identify the number, types and speeds of vehicles traveling those roads. Future road projects, whether adding lanes or going from gravel to paved, are an end result of the traffic counts.

Speed Limits – Speed limits changes are also influenced by traffic counts. Generally, a change in speed limit is based on the vehicle speed of 85% of the total vehicles traveling through the specific area counted.

Right-of-Way Encroachments

Encroachments in a public right-of-way present a safety hazard to the traveling public and Road and Bridge crews trying to maintain the County road. Encroachments can include landscaping, large rocks/boulders, earth or snow, yard debris, brick/stone mailboxes, signs and trenches among other things.

Idaho Code Section 18-3907 authorizes the Sheriff to issue a citation to anyone “…who obstructs, injures or damages any public road…”. Violation of this law is a misdemeanor (I.C. 18-113) and punishable by up to six months in jail and/or a $1000.00 fine. Property owners creating the obstruction/encroachment may also be liable for any injury or damage attributable to the hazard.

Mail Boxes


Mailboxes along all public roads shall follow the standards established by the U.S. Postal Service and more specifically Bonneville County:
• Property owners must use only approved traditional or contemporary mailboxes. Custom-built mailboxes may be used if the local postmaster gives prior approval and the mailbox conforms generally to the same requirements as approved manufactured mailboxes.

• Mailbox supports should be a semi-arch or extended arm type where drainage swales are located. This allows snow plows to sweep near or under mailboxes without damaging supports and provides easy access to the mailboxes by the carriers and customers.
• Mailbox supports should be no larger than a 4”x4” wood post or a 2” diameter standard steel or aluminum pipe buried no more than 24”. This type of post should safely break away without causing damage or injury if struck. Mailboxes shall not be contained in or built out of permanent materials (brick, stone, concrete, metal, etc).
• Mailboxes should be installed with the bottom of the mailbox at a vertical height of 41”-45" above the road surface.
• Mailboxes must be installed with the front being at least 2 feet horizontally off the road surface on local roads with speed limits less than 35 MPH; 4 feet on roads with a speed limit of 35 MPH; 6 feet on roads with speed limits from 40 and 50 MPH; 8 feet on roads with a speed limit higher than 50 MPH.
• Mailboxes must be on the right side of the road in the carrier’s direction of travel. The approach to the mailbox should be clear of snow, debris and other obstructions.


Property owners are responsible for the installation, maintenance and repair of driveway approaches. If repairs to a driveway are needed, it is imperative that the integrity of the drainage design be maintained for the free flow of storm water. Although not required by the County Public Works Department, a culvert (12" min.) may be installed underneath the approach to aid in the drainage. It is recommended that culverts be inspected periodically and cleaned out as needed.

Drainage swales along each side of the road are designed to carry storm water away from the road. The drainage swales on either side of the driveway should be clear of debris, rock and other landscape materials not allowed by the County to insure for proper flows.

Right-of-Way Landscaping

County arterial and collector roads generally have a 24 to 28 foot wide asphalt surface and are located in right-of-ways that can be 50 to 100 feet wide. Most subdivision or local roads have the same 24 - 28 foot roadway surface and are located in right-of-ways between 50 and 80 feet wide.

The area between the edge of the road surface to the right-of-way fence or property line is owned or controlled by the County and used, in most cases, as a barrow for snow removal and storm drainage. This area IS NOT set aside for landscaping although many adjacent property owners use it for that purpose.

It is unlawful to remove, fill in, or in any way change the barrow along a public road. Any landscaping (trees, rock, sprinklers, grass, etc.) installed in the road right-of-way MUST meet the landscaping standards in the Public Works Standard Specifications and Drawings. Prohibited materials in the right-of-way include steel/wood/fiberglass posts of any size and length, permanent and semi-permanent structures, non-breakaway mailbox posts, solid plastic or vinyl landscape fabric, large rocks/boulders and all fencing materials. Road & Bridge will not be responsible for any damage to landscaping located in the right-of-way.

Frequently Asked Questions

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