The Traffic Section of the Engineering Department is responsible for speed limits, changing or adding traffic signs, administrating the pavement marking program, collecting traffic volume data, keeping accident report records, and performing various traffic studies.

Pavement markings are a vital safety feature on most county maintained roads. Not only do they mark the center of the road and designate passing and no passing zones, they can also delineate the edge of the road, warn of railroad crossings, show where you should stop at a stop sign or traffic signal, create cross walks, and designate special lanes (bicycle and turn lanes).

All pavement markings are retroreflective, meaning they reflect light from headlights back toward the driver. This retroreflectivity is accomplished through the introduction of glass beads into the wet paint. When the paint dries, the beads are trapped throughout the thickness of the paint. As the paint line wears the beads on the surface wear off, while new beads are being uncovered.

Several factors effect the durability of painted pavement markings. Some of these are the traffic volume, the number and severity of snow storms (sanding of the roads wears the markings faster), curves in the road (traffic tends to cut the corner slightly), age of the pavement (newer pavements absorb more paint leaving less on the surface where it is needed), and paint formulation.

Maintaining these markings is quite expensive at over $200,000 per year to paint approximately 365 miles of road. Over 8,000 gallons of yellow paint and 9,000 gallons of white paint are applied annually. Nearly $10,000 of this program goes into durable marking work (preformed thermoplastic markings) which are used for stop bars, advance railroad crossing markings, crosswalks, turn arrows, "ONLY"s and other words, as well as channelizing lines.

Roads are repainted as the stripes get worn by traffic. Most roads require striping yearly while some require striping twice a year. The striping program also stripes the roads involved in the Road and Bridge Department's chip seal program. Roads with a fresh chip seal surface usually require two paint applications on the road centerline.

The Larimer County Traffic Section is responsible for counting traffic on the mainline county road system. Traffic count information is available through the Road Information Locater.

Standard traffic counts are taken using counters with rubber tubes stretched across the entire roadway. The counting stations are in place for a minimum of three days. The counts are recorded are bi-directional and represent a 24 hour period. These raw traffic counts can be adjusted to account for truck traffic and seasonal variations in traffic. The counts are typically taken on all legs of significant intersections. Roads are recounted on a two to five year cycle. Traffic count history for many roadway sections extends back to 1984.

The Traffic Section is also able to perform various special purpose counts including vehicle classification counts (identifying types of vehicles), hourly traffic counts (traffic volumes recorded hourly) and intersection turning movement counts. Due to the special equipment and personnel required for these types of counts, requests are prioritized and counts scheduled as people and equipment are available.

Traffic studies are an important part of the Traffic Section's work program. Studies are performed in response to citizen and staff requests. Studies include Speed Studies, Curve Studies, Sight Distance Studies, and Warrant Studies.

Each type of study concentrates on a particular traffic concern as described below:

  • Speed Studies look at speed limit postings along a section of roadway. These studies look at traffic speeds, pavement condition, surrounding land use, roadside traffic and parking, sight distance, and accident histories.
  • Curve Studies look at both horizontal and vertical (hills, dips) curves to determine the sight distance available according to criteria established by AASHTO (American Association of State Highway and Transportation Officials). The sight distance is used to help establish a reasonable speed limit for the curve.
  • Sight Distance Studies look at sight distance criteria to identify locations where a driver is unable to see far enough to enter or cross the roadway. These studies are often performed at intersections or intersection approaches and help identify locations where landscaping, signs, etc. block the driver's view. Obstructions may be removed or relocated to a different location or additional signing may be recommended to help in those locations where the obstruction cannot be moved.
  • Warrant Studies look at locations where multi-way stop signs or traffic signals may be warranted. The warrant studies look at criteria set up in the MUTCD (Manual on Uniform Traffic Control Devices). The MUTCD is the legal controlling document for these installations in unincorporated Larimer County.

Speed limits on publicly dedicated and county maintained roads in Larimer County are set based on several important criteria and changes must be supported by an engineering study. Some of the criteria used when setting or changing speed limits include:

  • Sight Distance (how far you can see) - Sight distance is how far a driver can see an object lying in the roadway. Sight distance is affected by curves, hills and dips. This distance corresponds to a maximum safe speed for that section of roadway.
  • Prevailing Vehicle Speeds - Measurements of vehicle speeds are taken during representative times of the day. The 85th percentile speed (85 out of 100 vehicles are traveling at this speed or slower) is compared with the posted limit.
  • Roadside Congestion (number of driveways and intersections) - The amount of roadside congestion affects how safely traffic can travel along a given piece of road. The more congestion, the more opportunity for accidents and near-misses. The primary problem being conflicts between fast moving vehicles on the road and slower traffic entering or exiting the roadway.
  • Surrounding Land Use (agricultural, residential, commercial, etc.) - Acceptable traffic speeds are lower in residential areas than in agricultural or open areas.
  • Condition of the Road Surface - If a roadway is smooth it can support a higher traffic speed than if it is rough.
  • Traffic Accidents - As traffic accidents increases (in number or severity) along a stretch of road the types of accidents are reviewed to see if the speed limits are potentially contributing to their number or severity.
  • Law Enforcement/Accident Reduction - The Colorado State Patrol and Larimer County Sheriff may request changes in speed limits.
  • Speeds on Adjacent Road Sections - Wherever possible, speed limits are set for significant roadway section lengths (often at least a mile).

Rarely will one of these criteria be adequate to justify a speed limit change. To balance the needs of the general public with adjacent property owners and customers it is often necessary to look at the "big picture" as well as the spot locations.

The Larimer County Engineering Department compiles an Annual Traffic Safety Report which highlights traffic trends, safety issues and problem locations for the calendar year.

2017
2016
2015
2014
2013
2012
2011
2010

Roundabouts are an effective means to decrease crash severity at intersections. Please take a look at this brochure containing general information and driving tips for single lane roundabouts.

Crash data are collected and used to monitor trends and problem locations on Larimer County maintained roadways. A map identifying crashes is available in Road Information Locator. Crashes are shown for the current year along with the previous three calendar years. Most crashes are available in the map within four to six weeks following the crash. Crashes on roadways not maintained by Larimer County are tracked by the entity who has jurisdiction for the roadway.

Eastern Larimer by Debbie Estep

Traffic Operations

Attn Traffic Operations
Larimer County Engineering Department
200 West Oak Street, Suite 3000
P.O. Box 1190
Fort Collins, CO 80522-1190

(970) 498-5707
Email