The following Q&A is based on a recent live tour of the All Roads Asphalt Plant in Coquitlam, BC, led by Rod Stephens, the company's president and a 40+ year veteran in the paving industry. During the tour, Rod walked engineers and staff from cities of Burnaby, Coquitlam and Surrey through the entire asphalt production process, explaining everything from raw materials to final mixes.
What follows is a simplified question-and-answer excerpt from that tour's "How Is Asphalt Made?" section—designed to help anyone understand what it takes to produce asphalt and what makes modern production both efficient and sustainable. Watch the full tour video below to learn more!
Asphalt is made by mixing rocks, sand, and a sticky black liquid called asphalt binder in a big heated drum. The rocks (called aggregates) are stored in bins, then sent into a rotating drum where they get really hot from a big flame. At just the right moment, the binder is added, and everything gets mixed together. Sometimes, old recycled asphalt and special fibres are added to make the mix stronger and more eco-friendly. Computers control the whole process, kind of like a recipe app, making sure each batch is just right before it's stored and ready to be sent out to build roads.
Rod Stephens:
Asphalt is a mix of aggregates (which are crushed rocks, gravel, sand) and liquid asphalt (also called binder oil or tar). We combine them in specific proportions to make what's called a mix design - basically a recipe. That recipe depends on what kind of road, lot, or surface you're paving.
Rod:
Asphalt binder (also called bitumen, binder oil, or sometimes just liquid asphalt) is the thick, sticky, black liquid that holds all the rocks and sand together in asphalt. It's made from the heaviest part of crude oil after fuels like gasoline and diesel are removed during the refining process. Think of it like the glue in a cookie - it's what binds all the ingredients into a solid, smooth surface.
Rod:
Asphalt is black mainly because of the asphalt binder. This binder is naturally very dark brown or black, and when it coats the hot rocks and sand during mixing, the entire mixture turns black. That's why paved surfaces made from asphalt are often called "blacktop." The color also helps roads absorb heat, which can speed up drying after rain but also leads to heat buildup in cities - a challenge known as the "urban heat island" effect.
Rod:
Think of it like your grandma's cookie recipe - some flour, sugar, maybe some nuts for crunch. In asphalt, it's similar. You choose different sizes of rocks, maybe a bit of sand, maybe add some fibre or recycled material - it's all about the right combination.
We currently make 32 different asphalt mixes here at our Coquitlam plant, all with different "recipes" depending on what the customer needs.
Rod:
This is the heart of asphalt mix design and why I lightheartedly compare it to grandma's cookie recipe. Here's how to reason through it. Think of it like this: you don't need hundreds of ingredients to make dozens of recipes - you just need to combine them in different ways. That's exactly how it works at the asphalt plant.
Now imagine those ingredients like Lego blocks. You can build many different structures (or in this case, asphalt mixes) just by:
Each combination produces a mix with specific strength, flexibility, durability, and texture - all tailored to the road's purpose (like highways, driveways, airports, or city streets).
So, even with limited base materials, by adjusting the ratios and ingredients, the plant can produce a wide variety of mixes - just like you can bake dozens of cookies from the same pantry by tweaking the recipe.
Rod:
We have cold feed bins - each one holds a different aggregate size. For example:
When someone says "3-bin asphalt," they mean a mix using three specific aggregates from those bins. Nowadays, it's all computerized - we just select the mix design, and the system pulls the right amounts automatically.
Rod:
That's where the drum comes in - it's the heart of the plant.
Rod:
RAP stands for Recycled Asphalt Product - it's old asphalt that's milled from roads and reused. We add it at the end of the heating process to preserve its binding properties. It's part of what makes our plant more sustainable and environmentally friendly.
Rod:
Fibre is like rebar in concrete. It adds tensile strength to asphalt.
Thousands of years ago, Egyptians added horse hair to their bricks - same concept. Fibre helps prevent cracking and rutting and gives better long-term performance.
We were the first in BC to use an automated fibre injection machine, which precisely sprays fibre into the mix and generates a report so engineers can see how much was used. Cities like Surrey, Coquitlam, the Ministry of Transportation and Transit (MOTT), and even YVR all use it.
It's also more cost-effective than using polymer-modified asphalt, which has to be shipped in from Alberta in large volumes. Fibre gives similar strength benefits but can be used in smaller, more flexible quantities - perfect for municipal jobs.
Rod:
It's all computerized now. Back in the day, operators had to manually time everything - press buttons, pull levers - down to the second. If you got distracted for a moment, the whole mix could be off-spec and wasted.
Now, computers handle the entire batching process for all 32 mix designs. It's more accurate, repeatable, and efficient. The operator just selects the recipe - it's like pressing a button on a coffee machine.
Rod:
Yes, they often ask for what we call a cold feed sample. That's just the mixed raw aggregates before they go into the drum for heating and binder injection. It gives a good preview of the aggregate quality and blend ratios.
Rod:
At its core, asphalt is a recipe of heated rock and oil, combined in precise ratios using modern automation. We've improved the process with recycled materials, fibre additives, and computer controls, making it more sustainable, higher quality, and cost-effective.
Asphalt production today is a blend of old wisdom and new technology. Whether it's RAP, fibre, or mix design software, everything's done to get the best performance on the road while being efficient and environmentally responsible.
Watch how Rod, our proud asphalt guru, bares it all and gives an in-depth explanation.
After marinating in hot asphalt fumes for over 40 years (figuratively, we promise), Rod has officially reached "Asphalt Nerd" status. If there's anyone on this planet who knows more about asphalt plants, hot mixes, and the mystical art of pavement perfection, it's Rod.
Recently, he led a brave group of city officials, engineers, and inspectors on an epic, hour-long walking tour of his asphalt kingdom. And when we say "tour," we mean a masterclass - Rod style. He dropped knowledge bombs faster than a machine gun at full throttle, sparing no detail and definitely no dad jokes.
Time was tight, the info was dense, and Rod was basically the asphalt version of a TED Talk... if TED was wearing a hard hat and steel-toed boots.
Let's just say-everyone walked away smarter, slightly sweaty, and maybe with a new appreciation for what goes into the road beneath their feet.
At All Roads, we're more than just asphalt producers — we're educators, innovators, and community partners. Our mission is to share knowledge and raise awareness about the latest advancements in asphalt technology. That's why we offer guided foot tours of our cutting-edge asphalt plant, located right here in the Greater Vancouver area.
During your visit, you'll follow the full journey of asphalt production — from raw materials like gravel and liquid asphalt cement (AC binder), to the finished product used on roads across the region. You'll also get an inside look at the science and strategy behind our 32+ custom asphalt mix designs: why they're developed, how they're applied, and what makes them essential for different infrastructure needs.
As Canada's greenest asphalt plant, All Roads is setting new standards in sustainable infrastructure. We use advanced technologies that reduce emissions, recycle materials, and improve energy efficiency — and we're eager to show you how.
We want to educate local engineers, municipalities, public works departments, and community leaders on the latest and most environmentally responsible asphalt solutions. From plant technology to lay-down systems, All Roads is proud to lead the way in innovation and environmental stewardship.
Whether you're a professional in the field or simply curious about how roads are made, we invite you to book a tour and discover what makes our facility — and our mission — so unique.
Let's build smarter, greener roads together!
Get ready to explore the 16 essential factors that power this plant’s environmental excellence.
The plant uses an Ultra II™ Low NOx burner - a high-efficiency combustion system that significantly reduces nitrogen oxides (NOx), which are major contributors to smog and air pollution. It achieves this by precisely controlling the air-fuel mix, maintaining uniform flame patterns, and lowering peak combustion temperatures.
This system sucks down and captures blue smoke or vapor emissions from silos and traverse units, reroutes them back into the drum, and uses heat to burn off pollutants. It's simple but highly effective.
Think of it as a giant, high-efficiency vacuum cleaner with 870 filter bags. It maximizes airflow while minimizing dust and emissions, outperforming conventional pulse-jet systems. Dusts collected are recycled back to the production process too.
Flue Gas Recirculation (FGR) reuses some exhaust gases to lower combustion temperature and further reduce NOx. Demisters remove oil mist from exhaust before it's released into the atmosphere.
Beneath the plant lies an advanced stormwater management and siltation system. All surface runoff is captured, filtered, and stored on-site - ensuring that treated water is safely returned to the environment. Oh, did we mention our entire property footprint is fully paved, which is not typical with asphalt plant sites?
These condensers, used on Hy-Way asphalt storage tanks, capture vapor emissions and convert them back into liquid. This allows the vapors to be recycled back into the tank instead of being released into the air.
Fuel choice matters. This plant runs entirely on natural gas - the cleanest-burning fossil fuel - eliminating the use of diesel or oil.
The plant features particulate sensors that continuously monitor air quality. It's like having a "Fitbit" for the exhaust stack - alerting staff immediately if anything is off-spec so it can be fixed fast.
A high percentage of Reclaimed Asphalt Pavement (RAP) is used in the mixes. This gives old roads new life - benefiting both the environment and the economy.
Our in-house lab is certified by the Canadian Council of Independent Laboratories. Built solely for quality control, it allows us to test materials before external inspections. We want to know exactly what we're laying on our roads.
Our control tower's automation system reads truck license plates, identifies tare weights, and loads each truck to full capacity. This reduces the number of trips required, lowering overall emissions.
Approximately half of our aggregates are delivered by barge, reducing the number of trucks needed on local roads.
Our yard is engineered with natural slopes to make the most of gravity, maximizing liquid asphalt usage and aiding in efficient stormwater management.
Diesel is not allowed on site - period. We provide an environmentally friendly release agent, free of charge, to prevent asphalt from sticking to truck beds.
By storing fine aggregates like sand under cover, we avoid using extra energy to dry wet materials - saving significant greenhouse gas emissions, especially in Vancouver's rainy climate.
Thanks to our highly efficient automated loading process, trucks spend minimal time idling in the yard - further reducing emissions.