In a collision between a car and a pedestrian at 50 km/h, the pedestrian has roughly a 10 per cent chance of survival. Drop that speed to 30 km/h and the survival rate jumps to 90 per cent. That single statistic explains why councils across Australia invest so heavily in traffic calming devices and why choosing the right one is not a minor procurement decision.
Yet when it comes to selecting between speed humps, speed cushions, and speed bumps, the differences are often misunderstood. Each device serves a distinct purpose, suits different road environments, and carries different implications for emergency access, maintenance budgets, and community acceptance.
This guide breaks down the practical distinctions, outlines what Australian councils typically approve, and explains where recycled rubber speed humps and cushions deliver the strongest outcomes for safety, sustainability, and long-term value.
The Challenge: One Label, Three Very Different Devices
Most community complaints about speeding end with a request for “speed bumps.” But in traffic engineering, that term refers to a specific device — one that is rarely the best answer for residential streets. Conflating speed bumps, speed humps, and speed cushions leads to mismatched installations, wasted budgets, and frustrated residents.
Traditional concrete or asphalt devices add another layer of complexity. They require excavation, curing time, and extended road closures. A single concrete speed hump can take days to form, pour, and cure, disrupting traffic flow and increasing project costs. Maintenance is equally demanding: cracked asphalt must be cut out and repoured, while faded markings need regular repainting.
For councils managing dozens or even hundreds of local streets, these costs compound quickly. According to the National Road Safety Strategy 2021–30, speed limit reductions, even as little as 10 km/h, have been identified as one of the lowest-cost, highest-value interventions for reducing fatalities and serious injuries. Physical traffic calming devices are a key tool for enforcing those lower speeds, making the choice of device all the more consequential.
The question for decision-makers is not whether to calm traffic, but which device fits the road, the budget, and the community. Getting this decision wrong does not just waste money; it can undermine community confidence in the entire traffic management process and delay future safety improvements.
Speed Bumps, Speed Humps, and Speed Cushions: What’s Actually Different?
Below is a clear breakdown of how bumps, humps, and cushions differ in shape and target speed. It also covers where councils usually allow each option, so you can match the device to the road from the start.
Speed Bumps
Speed bumps are the shortest and most aggressive of the three devices. They are typically 25–75 mm high with a very short traverse length (often under 300 mm), creating an abrupt vertical deflection that forces vehicles to slow to between 5 and 15 km/h.
They are most appropriate in private car parks, loading docks, and low-speed internal driveways where pedestrian activity is high and vehicle throughput is low. Under AS 2890.1:2004, Type 2 speed humps (which cover most car park applications) must meet specific requirements for height, cross-section, ramp angle, and markings.
Speed bumps are rarely approved for public roads because their abrupt profile can cause driver discomfort, increase braking noise, and create issues for cyclists and motorcyclists.
Speed Humps
Speed humps have a longer, more gradual profile than bumps—typically 3–4 metres in length with a height of 75–100 mm. The gentler ramp angle means vehicles can cross at around 20–30 km/h without excessive discomfort, making humps far better suited to residential streets, school zones, and connector roads.
Rubber speed humps are increasingly favoured over asphalt or concrete versions. Manufactured from recycled rubber, they offer faster installation, lower lifecycle maintenance, and consistent performance in Australia’s harsh UV and weather conditions. Councils also appreciate the environmental credentials: diverting rubber from landfill while delivering a product that lasts.
The main limitation of full-width speed humps is that they slow every vehicle equally, including buses, ambulances, and fire trucks. On designated emergency routes or bus corridors, this can be a significant approval barrier.
Speed Cushions
Speed cushions are the device that solves the emergency-access problem. They use the same height and profile as a standard speed hump, but they are narrower and installed in sections across the carriageway with gaps (cutouts) between them.
These gaps are sized so that wide-axle vehicles like fire trucks, ambulances, and buses can straddle the cushions and pass through with minimal vertical deflection. Standard passenger cars, however, cannot straddle the raised sections and must slow down, typically to 15–25 km/h.
Research published through the US Federal Highway Administration’s Traffic Calming ePrimer found that speed cushions reduced the 85th percentile vehicle speed by an average of approximately 25 per cent — comparable to traditional speed humps.
Crucially, the same research noted that fire departments reported a positive response to speed cushions, with minimised increases in emergency response times and less discomfort for personnel inside the vehicles.
This combination of effective speed reduction and emergency-vehicle compatibility is the primary reason many Australian councils now mandate speed cushions over full-width humps on streets that serve as emergency-response or bus routes.
Rubber speed cushions also generate less noise than full-width humps when vehicles cross them, which matters in residential settings where night-time traffic noise is a common concern.
Their modular design means individual sections can be replaced independently if damaged, rather than requiring a full device replacement. For councils managing tight maintenance budgets, that modularity translates directly into lower whole-of-life costs.
Quick Comparison at a Glance
| Speed Bumps | Speed Humps | Speed Cushions | |
| Best For | Car parks, private driveways | Residential streets, school zones, low-speed local roads | Bus routes, emergency corridors, collector roads |
| Target Speed | 5–15 km/h | 20–30 km/h | 20–30 km/h (passenger vehicles) |
| Emergency Vehicle Access | Slows all vehicles equally | Slows all vehicles equally | Wide-axle vehicles pass with minimal delay |
| Primary Standard | AS 2890.1:2004 | AS 1742.13 | AS 1742.13 |
| Available in Recycled Rubber | Yes | Yes | Yes |
| Public Road Suitability | Rarely approved | Strong | Strongest (council-preferred on emergency/bus routes) |
Why Recycled Rubber Is Replacing Concrete for Traffic Calming in Australia
Concrete and asphalt speed humps have served Australian roads for decades, but recycled rubber alternatives now deliver a stronger proposition across nearly every metric that matters to councils and contractors.
- Sustainability: Rubber speed cushions and humps from Traffic Products Australia are manufactured from 100 per cent recycled rubber, diverting waste from landfill and reducing the carbon footprint of every installation. For councils reporting against sustainability targets, this is a measurable, auditable benefit.
- Installation speed: Modular rubber systems bolt directly to asphalt or concrete surfaces with no excavation, curing, or extended road closures required. Where a concrete hump might take days to complete, a rubber speed cushion set can often be installed within hours. That translates directly into lower traffic management costs and reduced disruption for residents and businesses.
- Durability and low maintenance: Recycled rubber withstands UV exposure, temperature extremes, and heavy vehicle loads without cracking, fading, or deforming. TPA’s rubber speed cushions are engineered to handle loads of up to 80,000 pounds. Integrated reflective markings and high-contrast colour moulding eliminate the ongoing cost of line-marking maintenance.
- Relocatability: Because rubber systems are bolted rather than poured, they can be removed, relocated, and reinstalled without destruction. This is especially useful for trial installations, where councils want to test a traffic calming layout before committing to a permanent configuration.
For a broader look at how rubber-based products are transforming traffic management, see our guide for rubber solutions for traffic calming on the Traffic Products Australia blog.
It is also worth noting that rubber devices perform consistently across Australia’s diverse climate zones. Whether installed in the tropical heat of northern Queensland or the cooler conditions of southern Victoria, recycled rubber maintains its structural integrity and surface grip. Concrete, by contrast, is susceptible to cracking in extreme temperature cycles and can become slippery when wet unless treated with additional non-slip coatings.
Implementation: From Specification to Installation
This is how the process usually runs, from design and approvals through to installation and maintenance.
Design and Specification
Getting the design right from the start prevents costly rework. Key considerations include road width, traffic volume, the presence of bus or emergency routes, drainage, and kerb alignment. Traffic Products Australia’s principal design engineer works with councils and contractors to develop layouts that meet both Australian standards and site-specific requirements. This in-house design capability means you get a solution that fits the road, not a generic template.
Council Approval
Council approval processes for traffic calming devices vary between jurisdictions, but common requirements include compliance with AS 1742.13 (for public road devices), adequate signage (W5-10 hump warning signs where visibility is limited), appropriate line-marking, and consultation with emergency services where speed cushions are proposed on response routes. Using products that already meet Australian standards streamlines the approval process and reduces the risk of post-installation compliance issues.
Installation and Timeline
Rubber speed cushions and humps are installed using a bolt-down method. The modular interlocking segments are positioned on the road surface, aligned, and anchored with mechanical fixings. No excavation, formwork, or curing period is required. Most installations are completed within a few hours, with the road reopened to traffic immediately.
Compare this with concrete, which typically involves excavation, forming, pouring, curing (often 7+ days for full strength), and separate line-marking. The total project timeline and cost difference is significant, particularly for multi-site rollouts.
Ongoing Maintenance
Recycled rubber devices require minimal maintenance. Periodic inspection for bolt tightness and surface wear is generally all that’s needed. Because colour and markings are moulded into the rubber rather than painted on, there is no line-marking refresh cycle. TPA backs its products with an industry-leading 5-year product guarantee, giving councils and contractors confidence in long-term performance.
If you’re evaluating broader traffic calming strategies, our guide on effective traffic calming strategies for residential zones provides additional context on integrating speed cushions with other measures for residential areas.
Key Takeaways: Getting It Right the First Time
- Match the device to the road function: Speed bumps belong in car parks, speed humps on local residential streets, and speed cushions on collector roads or any route used by emergency services or buses.
- Consult emergency services early: If fire or ambulance services express concerns about response-time impacts, speed cushions with appropriate cutout widths are almost always the approved alternative to full-width humps.
- Specify recycled rubber for sustainability and lifecycle value: Rubber devices install faster, last longer without repainting, and support council sustainability reporting — all while diverting waste from landfill.
- Demand a product guarantee: A 5-year guarantee is the benchmark for quality rubber traffic calming products. If a supplier cannot offer one, question the material quality.
- Plan for the trial-to-permanent pathway: Rubber’s bolt-down installation means you can trial a layout, gather community and traffic data, and then either confirm or adjust it—without demolishing anything.
- Think beyond the individual device: Speed cushions and humps work best as part of a broader traffic calming strategy that may include raised crossings, kerbing, chicanes, and signage. An integrated approach delivers stronger speed-reduction outcomes.
Safer Roads Start with the Right Device, and the Right Partner
The difference between a speed bump, a speed hump, and a speed cushion is not just technical — it determines whether your installation gets approved, whether emergency access is maintained, and whether the community sees a genuine improvement in road safety.
Traffic Products Australia has spent over 20 years helping councils, contractors, and traffic planners across Australia choose and install the right traffic calming solution for every situation. With in-house design expertise, 100 per cent recycled rubber products, end-to-end project support, and a 5-year product guarantee, TPA makes it straightforward to deliver safer, more sustainable streets.Ready to specify the right speed cushion or hump for your next project? Contact Traffic Products Australia on 1800 211 212 for a free consultation and quote.
