Streets

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Paving & Surface Treatments
The Infrastructure Department provides repair services to Thornton's streets. Such repairs may include potholes, crack sealing, street failures, and unimproved road grading.

Street Rehabilitation Program
The project includes rehabilitating city streets as determined by the Pavement Management System and staff recommendations. Rehabilitation includes asphalt overlays, crack seal, hot chip seals, street concrete replacement (curb, gutter, cross-pans), and accessible ramp replacement as required. Both city crews and contractors participate in the Street Rehabilitation treatments and locations. Project locations are shown on the map under featured links.

Concrete Replacement Program  
City Council has approved a $ 140,000-a-year budget to replace broken or damaged concrete within the city. The severity of damage determines locations for replacement as they relate to pedestrian hazards, structural damage, surface deterioration, and impact on drainage. Work generally begins in March, weather dependent, and can last several months.

Crack Seal: Why does my street crack?
Cracks can form in asphalt pavement through various modes of distress. Regardless of how the cracks form, they must be repaired to help protect the pavement structure. If the cracks are not maintained, they can ravel and increase in size. Unsealed cracks allow water to penetrate the structure from the pavement surface, which eventually causes potholes and further deterioration. Water infiltration is the number one enemy of pavement. Crack sealing is the most important and cost-effective maintenance option to help protect the integrity of the pavement.

Benefits of Crack Seal:

• Prevents water from entering the pavement and sub base
• Prevents debris from entering the crack
• Prevents or delays pothole formation
• The life expectancy of Crack Seal is approximately 3-5 years.

Crack Seal Program
The Street Rehabilitation Program has developed a city-wide crack seal program that addresses every street in the city every five years. A contractor applies this crack seal. Street Operations also uses crack seals as needed in areas of safety concern (crosswalks, for example). After each crack seal application, the area is evaluated for mastic application. Mastic is a crack fill application that addresses cracks with a deflection that impacts the drivability of the roadway.

Hot-In-Place Recycling
Hot-In-Place (HIP) recycling is a single-pass repaving process using specially designed equipment in a simultaneous, multi-step process that removes some of the existing asphalt, reheats and recycles it with a rejuvenating agent and then is placed on the road surface with additional new Hot Mix Asphalt set on top of it. This process provides a smooth, restored riding surface.

Benefits of Hot-In-Place Recycling:

• Improves the smoothness, durability, and appearance of the street with like-new results
• Minimizes traffic delays because of its single-pass process
• Environmentally friendly by reusing existing asphalt
• HIP recycling has a life expectancy of approximately 8-10 years.

Hot In-Place Recycling: This option is used instead of a typical Mill and Overlay operation. The city of Thornton uses this process on all asphalt street types (Arterial, Residential). A benefit of using this process on residential roads is the minimal impact on residents. The HIP is a shorter paving process that allows residents to return to their streets sooner.

Hot Chip Overlay
Hot Chip Overlay is a two-step surface treatment combining a Chip Seal and a thin overlay of open-graded friction course (Hot Chip Seal) providing a double material application. This provides a waterproof membrane, and the Hot Chip Seal provides a strong wearing surface that will improve the profile of the existing asphalt.

Benefits of Hot Applied Chip Overlay:

• Improves skid resistance and safety with a high-friction surface
• Provides asphalt pavement with additional structural strength
• Quiet surface treatment especially on high-volume traffic roads
• Enhances the appearance of the road by improving the surface texture, profile, and surface color
• Hot Chip Overlay has a life expectancy of approximately 8-10 years.

Since the Hot Chip Overlay is a two-step process, it will leave the road bumpy at points during its construction, and slowing down is the best thing drivers can do until the final overlay is applied in the second step of the process. During the Chip Seal process, drivers may encounter loose rock and should give extra distance to the car in front to avoid being struck by the loose material.

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Asphalt Rejuvenator
Asphalt Rejuvenator is a liquid product sprayed on the road, rehydrating the asphalt binder (black stuff) that holds in the aggregate. By rehydrating the asphalt, binding the roadway will lose less aggregate and result in fewer potholes. Rejuvenators can be thought of as having the same results as a lotion for skin.

Benefits of Rejuvenators:

• Cost-effective preventative maintenance treatment
• Holds the aggregate in the roadway
• Tightens and closes hairline cracks in the asphalt
• Reduces potholes and large cracks
• Asphalt Rejuvenator has a life expectancy of 5-7 years
• Asphalt Rejuvenators are typically applied to Residential streets, and have a quick application time minimizing impact to residents.

Asphalt Mill/Pave
An asphalt mill/pave operation is the application where the top layer of asphalt is removed and replaced with new Hot Mix Asphalt (HMA). HMA is mixed, placed, and compacted at elevated temperatures, hence the name. HMA combines approximately 95% stone, sand, or gravel bound together by asphalt cement, a product of crude oil. Asphalt cement acts as the glue to hold the pavement together. The resulting Hot Mix Asphalt is loaded into trucks for transport to the paving site. The trucks dump the Hot Mix Asphalt into hoppers at the front of paving machines. The asphalt is placed and then compacted using a heavy roller, which is driven over the asphalt. Traffic is generally permitted on the pavement as soon as the pavement has cooled.

Asphalt is America's most recycled material. The city of Thornton's HMA contains approximately 20% recycled asphalt. Recycling is just one reason that asphalt is such a sustainable pavement.

Benefits of Hot Mix Asphalt Mill/Pave:

• Less expensive than complete removal and replacement
• Removes surface damage to street
• Can improve drainage in streets
• Re-establishes proper grade
• Improves surface for smoother driving and better traction
• HMA has a life expectancy of approximately 10-15 years, depending on the traffic volume.

Asphalt Base Patching with Geogrids
The city of Thornton utilizes a base patching with Geogrid textiles in its Street Rehabilitation Program to reduce the amount of deep cracking in asphalt pavement. This process includes milling (removing) an additional 3"+ of asphalt and placing a Geogrid textile mesh over the deep crack; the area is then backfilled with new Hot Mix Asphalt, and a wearing course (see above) is then applied over the entire street.

Benefits of Asphalt Base Patching with Geogrids:

• Dramatically reduces the amount of reoccurring cracks
• Stabilizes the bottom layer of the roadway
• Provides longer life for the wearing surface course

Asphalt Base Patching with Geogrids combined with a surface-wearing course has a life expectancy of approximately 7-10 years, depending on the traffic volume.

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​The Infrastructure Department performs the Street Sweeping Program. The service levels provide for cleaning major thoroughfares and collector streets four times annually. The Infrastructure Department will be performing residential street sweeping programs. Street sweeping will be conducted as needed and only then to address hazardous or health-related conditions. 

View the Contractor Fall Sweep Map [PDF/5.4MB]

Colorado's winter driving conditions can change from sunny to blowing snow in minutes. Be prepared at all times, but especially in winter. Know the road conditions, know your vehicle, use proper driving techniques for the conditions, and have the right emergency gear and equipment along with you. Below are some safe driving tips.

​Snowplows
When you approach a snowplow from behind, pass with care and only when you can see the road ahead. You should not try and pass in blowing snow. There may be a vehicle in that cloud of snow! Allow more distance between you and the plow, they may be spreading sand or chemicals. Be alert when you approach a cloud of snow that covers the road, especially on passing lanes of the interstates or freeways. Slow down and approach with caution. A snowplow may be clearing snow in that lane or preparing to turn around.

​Winter Ready
Because winter is so rough on equipment, you should regularly check the wipers, tires, lights, and fluid levels (radiator, windshield washer, power steering, oil and brakes). Make sure brakes and transmission are working properly. If you suspect trouble, check it out. It is better to be safe than sorry!

Your vehicle should be equipped with a winter emergency survival kit. The following items are recommended:

• ​Ice scraper, snow brush, rags and paper towels.
• Jumper cables, basic tool kit, antifreeze, and no-freeze windshield washer fluid. 
• Shovel, mats or old rugs for traction, tire chains, salt, sand or kitty litter. 
• Blankets or sleeping bag and extra clothing including hats, socks, waterproof boots, coat and gloves. 
• Non-perishable, high calorie food. 
• Candles, waterproof matches and metal container such as a coffee can for melting snow. 
• Flashlight and extra batteries, flares or roadway reflectors. 
• Basic first aid kits and fire extinguisher.

Vehicle Operation
Winter driving is often the most difficult driving due to blowing snow, icy slick spots and fewer daylight hours.

When you are on the road you should:

• ​Buckle those seat belts! (It's the law). 
• Be prepared to turn back or seek shelter if conditions become bad. 
• Keep your windows clear of snow and ice.  Do not start off until your windshield is defrosted. 
• Drive slower and increase your following distance.  Your speed should be adjusted for the conditions and flow of traffic. 
• Roadway conditions may vary widely due to sun, shade, or roadway surface.  Watch for slick spots especially on bridges, overpasses, and shaded spots. 
• If the pavement is snow or ice covered, start slowly and brake gently.  Begin braking early when you come to an intersection. 
• Be careful after a minor accident.  If you do not feel comfortable exiting your vehicle, motion the other driver and drive to the nearest police station, 24-hour store, service station, hospital, or fire station.

​Stuck or Stranded
If your vehicle breaks down, pull as far off the road as possible.  Your greatest personal danger at this point is that of being hit by a passing vehicle.  Don't panic.  Do not over exert yourself, especially when shoveling snow or pushing a stalled or stuck vehicle.

If you are stranded on a well traveled road, wait for assistance from police or other emergency service providers.  Raise the hood, turn on the dome light and flashers to make your vehicle more noticeable and attach a cloth to the antenna or windows. Cell phone owners who see stranded motorists can do them a favor by calling and reporting the exact location and description of the vehicle.

​Back Home
​When you return home from a winter trip, wash your vehicle to remove dirt and road salt.  A coat of wax will help protect the finish from the effects of salt.  Lubricate door and trunk locks to prevent them from freezing.

We hope this information will help make your trip both safe and enjoyable.

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Street Snow Removal
After major snow events, as the snow melts, it will flow into shaded areas and refreeze, causing ice jams. The goal with ice jam treatment is to remove the hazard to the traveling public; in most cases, this does not result in complete ice removal but treating as needed and allowing temps and sunlight to assist in the complete removal. This is the most cost-effective and efficient process to maintain almost 1,320 lane miles of streets in Thornton.

Snow Removal Information Video

The first step is to apply an ice slicer to the ice jam location, the same material used during the snow event, which leaves brownish sand-looking material on the roadway. This material melts the ice quicker than salt but isn't as corrosive. Often multiple rounds of ice slicer are utilized to treat an area. If the ice slicer is not working to remove a hazardous condition, the ice jam will be removed mechanically using heavy equipment. Using heavy equipment is a last resort as it has the potential to damage infrastructure (roadways, sidewalks, landscape) and is expensive and slow.

Below you can watch a short video of hard-working staff plowing in formation during a snowstorm. Note the additional "plow wing" on the lead truck that lets the operators plow a few more feet of roadway each pass. The wing can be raised and stowed out of the way with the push of a button. Three of the four trucks have a live bottom system, which spreads the ice slicer before the rear wheels for better traction, while a third truck in line has a v-box spreader at the rear of the truck.

How I can help as a Citizen:

• While ice can possibly accumulate in the gutter, we can apply Ice Slicer for melting and traction.
• With early notification, ice build up can be slowed down or eliminated.
• Together, these can help alleviate the use of heavy equipment and possible damage to city infrastructure.
• Shovel snow onto the sun exposed areas of your lawn and garden and not into roadways and bike lanes. This prevents ice from building up in the gutters, causing problems after the storm.
• Park 6" to a foot from the curb to allow meltoing snow to pass.
• Shovel early! When snow isn't shoveled, it gets packed down and becomes ice.
• Shovel snow all the way to the pavement prevents ice from forming.
• Use ecofreindly and pet-safe deicers. Salt can be damaging when the snowmelt runs off onto your lawn or into the storm sewer.
• Use the shovel to push the snow. Don't lift it. 
• Submit a snow removal service request through My Thornton.

Our Task
Thornton has over 335 miles of Primary Streets (like 120th Avenue and Colorado Boulevard). There are 208 Secondary Streets (like Eppinger Boulevard and Cottonwood Lakes Boulevard) and an additional 619 miles of residential streets, totaling more than 1,300 miles of road within city limits. Snowplows continuously plow all Primaries to keep roads open, followed by Secondaries routes as weather permits.

​​​​​​The city divides storms into three classes and responds accordingly.

• Class I - A storm that lasts less than 12 hours with snow accumulations of less than 4 inches.
• Class II - A storm that lasts more than 12 hours with snow accumulations between 4 and 8 inches.
• Class III - A storm lasting more than 24 hours and snow accumulating over 9 inches.

In any snowstorm, the city's first commitment is to clear the Primaries, then the Secondaries — and keep them cleared. In the case of a Class III storm (and only in this case), the city will bring in additional equipment to plow residential streets. Residential streets will receive one pass down the middle of the street, not a curb-to-curb street clearing, and the snow will be plowed to the right side of the street.

During large storms, snowfall may be so heavy that only Primaries can be maintained in a passable condition until the storm lets up. When Primaries are clear, then Secondaries are plowed.

​​Streets - First Attention  
Priorities - The first priority for city plows is the primary routes: the major arterial streets such as Colorado Boulevard, Washington Street, 104th Avenue, 120th Avenue, and 136th Avenue. Next to be plowed are the secondary routes, including local collector streets, school zones, and fire station zones. As defined above, residential streets are only plowed for a Class III storm.

​During a Storm - In Class I or Class II storms, city crews will plow only selected streets identified as Primary and Secondary routes. Primary and Secondary routes comprise 543 lane miles of Thornton's street system. In a Class I storm, Primary routes are treated within three hours of snow accumulating on roadways. After the primary routes are completed, secondary routes will be cleared of snow and ice.

Tertiary Routes - In the event of a storm, which meets the Class II definition plus a prolonged period of freezing temperatures, a decision is made to plow Tertiary routes, which include an additional 55 miles of neighborhood streets. These routes are cleared by Street Operations personnel once the primary and secondary streets are cleared and treated. These routes will receive one pass down the middle of the street, not a curb-to-curb street clearing.

During Class II and Class III storms, snowfall may be so heavy that only Primary routes can be maintained in a passable condition until the storm abates. When Primary routes are clear, then Secondary routes are plowed. Residential streets are only plowed during Class III storms.

Residential Streets and Plowing Shifts  
Residential Streets - Residents will not necessarily see bare pavement after plowing residential streets. The emphasis for residential streets is to create a single passable lane down the middle that can be navigated by passenger vehicles equipped for winter travel.

Blocked Driveways - During heavy snowfalls, problems arise for residents when mounds of snow are left on the sides of streets, which may block driveways, also known as windrows. Although a concerted effort is made to avoid this, it is not always possible. Residential streets are plowed down the center of the street to prevent covering sidewalks and parked cars or blocking driveways. The city of Thornton does not remove or haul away snow as part of this program, and it is the resident's responsibility to clear these windrows.

Snowplow Deployment and Shifts - When the snow hits, all of our crews and equipment work 12-hour shifts, and in the event of a Class III storm, the city also has its contractors working to remove the snow.