Most people tend to use the words “road” and “street” interchangeably. So it may surprise you to learn that streets and roads are two very different concepts, with different functions and purposes.
The Oxford Dictionary explains that a road is “a wide way leading from one place to another, especially one with a specially prepared surface which vehicles can use”. While a street is a “public road in a city, town, or village, typically with houses and buildings on one or both sides”.
It makes sense why, in the British vernacular, we shop at a “high street” not a “high road”. It also makes sense why the Roman Empire expanded rapidly by building roads to reach across and through much of Europe.
A road is primarily about moving people and goods. A street is about a place for public life that has many functions including movement.
It is important as the designers and makers of our future cities and towns that we use the terminology for what we mean and importantly, what we are trying to achieve.
Our streets and roads account for the largest portion of the public domain in any city or town. They are a valuable resource and by recognising the differences in their function and character, we can design and develop better places for us to live.
In Australia, we focus too heavily on roads. There are no government agencies for streets, but every state or territory with a dedicated agency has “road” in its title. This makes sense when we put it in the context of post-war growth and our emerging love affair with the private vehicle and the quarter-acre block.
Building roads enabled us to rapidly expand our suburbs, our economy and we had the land to do it. Suddenly we could access places quickly that were out of reach of public transport. This model was so successful that we continued to replicate it, and people’s travel patterns and preferences changed.
The results of these changes included the extensive tram network in Sydney being decommissioned as it no longer had the demand to support it.
We also witnessed public investment focus on road building, which saw the expansion of the 19th century rail network in NSW stagnate.
As we become more heavily populated, urbanised and live in places with greater density, we have to be smarter about how we design and deliver our cities and towns, and how we move people within and between places.
We are moving our forms of living up rather than out because we have less space to play with. Less space and more people means we need to focus on moving people and goods efficiency.
Our success with the car-based model of road building is not suitable for our urban future. If we know that we need to be more efficient, as we have more people and less space, we need to demand higher productivity of our existing network. That means more public transport (it’s got a high capacity-to-volume ratio), walking and cycling (both are space efficient).
“What about autonomous vehicles (AVs)?” you may ask and although AVs are likely to increase safety and potentially reduce the average vehicle size, without significant shift in people’s behaviour, it’s likely that they will still be inefficient due to their size, number of people they can move at once, and they require land for storage (which could be otherwise allocated to a better use).
Roads are well-suited for movement functions (shown in figure 1 toward the left), but to increase their productivity, we need to do better about allocating and prioritising road space to efficient modes (for example, real and meaningful priority for buses including lanes and signal priority) and freight purposes.
Often, we see roads put in places where there should be streets. Streets are over-engineered for “future growth” to the point that their purpose and function as a street is diminished, and instead we have a road with buildings beside it.
Let’s make streets where we need them, and for the communities that they serve. Street design should be as diverse as people and landscape, but we insist on codifying, sterilising and separating different users (this is why we have separation through the use of kerbs, footpaths and carriageway – and drainage can be done without kerbs!).
We are told we are separated to keep us safe, but rather it is because for so long we have created streets that are roads, and these roads are designed to instruct people driving cars to move quickly through and area (and is another reason why we get so annoyed about congestion).
If we go back to the definition of a street, the important factors are:
It is for public use; and
It is located in a place with activity and variety of land uses.
What if street design was framed with this in mind? How would we expect people’s behaviour to change when they used it? How would we change our approach to design and safety?
We like to keep our streets well-dressed in Australia. Fully clothed in all their signage, line markings, signals and barriers to make sure that people walking, driving or riding stick to their designated part of the street or road.
We know in major city centres that pedestrians make up the majority of users, yet have the least street space allocated to them.
Our current method for designing streets is centred around the car. We define the shape and function of the street on this metric. The metric used is a mathematical construct we call “trip generation”, which then allows us to calculate the “level of service” (LoS).
Put simply, the level of service measures how easily traffic moves through an intersection. The level of service metric impacts every planning decision made to shape our public domain.
Level of service runs from A, which is considered good, to F which is considered very bad; ideally, road agencies want roads and streets to function at LoS A, B or C.
So, why is an objective measure of how easily traffic moves through a street potentially bad and what does it mean for street design?
When LoS starts creeping into LoS E and F, that’s when a serious look is taken to upgrade the street. Upgrade almost universally means “make bigger”, and we make bigger to cater for more cars, not people.
This cause-and-effect scenario is based on a very simple assumption: When places grow, more people drive, therefore we must build more roads. That makes sense to most of us, but what happens when that extra space fills up with cars?
We are at a critical juncture within our cities where we are literally running out of space to build more roads.
Road agencies are turning to tunnelling to “reduce impact on streets” yet that doesn’t cater for the fact that people need to drive to and from the tunnels on local streets which delivers more traffic, and these exit or entry points often mean massive intersections and local street widening to cope with the high demand.
We don’t reduce congestion by building more roads; what we actually need is less cars.
To make that happen with a growing population, we need more public transport (which uses the road but carries far more people per metre squared than a car can, even when that car is full of people – which almost never happens, by the way) and active transport to complement the contingent of people who actually need to drive.
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