Liveable Arterials

Imagine we stop driving cars so much.

Imagine having traffic levels like those in Level 4 Lockdown, when only essential journeys were taken by car – as a normal traffic environment.

Put on ice for a moment any doubts about whether we could or should do this… and let me paint a picture of our streets if we managed to do so.

This post is about the change enabled on the “arterial” and “connector” roads – the streets that will form the boundaries between low traffic neighbourhoods:

I believe we can recreate these streets so they become “liveable arterials”. I believe they can function much better for all the people that use them, whether they are on foot, in wheelchairs, moving freight, travelling by bus or bike or other small wheeled ‘micromobility’. As I said in Yes! We can do all those sorts of things, it became visible during Level 4 Lockdown that:

We can fit walking and cycling and buses and trucks and essential car journeys in the corridors we have.

What our corridors don’t have space for are the discretionary car journeys; trips that could be taken by other modes but instead are driven, creating congestion. Which is why my starting premise is that we reduce how much we drive.

So let’s squint and imagine what our streets can be.

Example One: A typical Auckland street

Preston Rd in East Auckland is a typical 20.1m wide road corridor with one traffic lane in each direction, flanked by a parking lane on each side, plus a flush median.

The footpath environment is ok, and there are trees. The biggest deficiency is the lack of safe cycling infrastructure.

Cyclelanes need the following space:

• Unidirectional cyclelanes – a minimum width of 2.4m to allow a person on a cargo bike to overtake a person on a bike, or vice versa. At pinch points this could be reduced, preferably to no less than 1.8m or 2m, or
• Bidirectional cycleways – a minimum of 3m to allow cargo bikes to pass each other safely.
• Buffers – 500 or 600 mm wide at a minimum.

These dimensions are given by Auckland Transport in their Transport Design Manual:

To provide this space, we would need to remove:

• Parking lanes – with much lower traffic volumes, car ownership rates would drop. In any case, when space is at a premium, safe cycling has priority over parking.
• Flush medians – at vehicle speeds suitable for a city, 30 km/hr, a protective buffer is needed between vehicles and people outside vehicles, not between lanes of vehicles.

By making these changes, Preston Rd would look like this:

Instead of hit sticks, we’d choose a type of protective barrier that is strong, attractive, easy to install and low cost. With hundreds of km of streets like this in Auckland, economies of scale could make the process very cheap.

A central pedestrian island at pedestrian crossings could be achieved with some very local reallocation of the footpath space:

Example Two: A Bus and Freight Route

Great North Rd in New Lynn is also 20.1m wide.

The footpath environment in this location is really poor. It’s been narrowed, and any street trees removed.

Transport planners have forced high vehicle volumes through, adding traffic lanes at the expense of walkability and cycling safety.

By removing just one traffic lane, cycle lanes will fit alongside the three remaining traffic lanes; the third one could provide lengths of dedicated bus lanes for each direction in turn. Walking would be improved by having the bikes, rather than motor vehicles, adjacent to the kerb:

However, the footpaths are still too narrow, and will continue to be extremely cramped at bus stops. Extra pedestrian crossings are needed, but there’s no space available for safe pedestrian islands.

Changing the two unidirectional cycleways to one bidirectional cycleway would save space, but it’s not a good solution: it wouldn’t safely deliver people on bikes and scooters (including children, people going about their work, elderly people, deliveries) to properties on the other side of the street.

The best solution, therefore, involves reducing the number of lanes down to just two.

At the tactical stage, before kerbs and drains are moved, able-bodied people might need to step down to the footpath at carriageway level to pass those with wheelchairs or prams:

The permanent design would involve extending the footpaths, and planting trees:

There’s sufficient space for pedestrian islands:

And for bus shelters:

Let’s look at who benefits from these changes.

Bus Passengers

The altered streetscapes would benefit bus passengers:

• Getting to the bus stop is much safer and more pleasant. Bus passengers would be able to walk, scooter, bike, or use wheelchairs to the bus stop.
• Shorter crossing distances, fewer lanes of traffic to cross, and pedestrian islands create a much safer environment, particularly when running to catch a bus.
• There’s much more space available at the bus stops, which would make a big difference for both bus passengers and passersby.

To be attractive, buses also can’t be stuck in congestion. On key rapid transit routes, dedicated bus lanes are best, but on these “liveable arterials” there’s a need for fewer motorised traffic lanes, and more safety. We don’t have space for dedicated lanes, so reducing traffic is the best way for getting buses out of congestion.

These measures can also help:

• Excellent enforcement of no stopping areas
• Giving buses the right of way when pulling out of a bus stop and at roundabouts,
• Using in-line bus stops so they don’t need to merge with any traffic,
• Giving buses green lights automatically by detecting them as they approach traffic signals.

Pedestrians

Walking would be much nicer: As well as the wider footpaths, and trees, the cyclelanes separate the footpath from the traffic by a distance which will both reduce noise – meaning conversations will be easier – and improve safety, especially for young children.

If we design our streets for people with the highest accessibility needs, many people across the whole population will benefit from feeling like they don’t need to drive, helping reduce traffic volumes.

Freight and business traffic

Logistics is undergoing a rethink in many international cities, involving:

• Reducing the size of trucks in cities for safety reasons
• Directing trucks to hubs and using “right-sized vehicles” like e-cargo bikes and e-vans to distribute to/from the hubs
• Approaching the problem of congestion, and the toll it takes on efficiency, by reducing traffic.

While it seems businesses would benefit from a freight priority lane, their biggest need is actually cycle lanes, to:

• Allow modeshift to e-cargo bikes for deliveries, and
• Allow staff to have healthier lifestyles, cycling to work, and set free from the exhausting business of being taxi-driver for non-driving family members.

In Michael Eliason’s 26 Climate Actions Cities Should Adopt at COP26 for Climate Change Resilience he included:

10. E-Cargo and Cargo Bike Logistics

Non-polluting, fast, and easy cargo bike logistics should be prioritized in urban areas. Cargo bikes can play an outsized role in last mile solutions. Plus, they’re incredibly quick and affordable versus the cost of cargo vans, gas, and parking tickets. Cargo bikes also play well with trams, offering the potential for really interesting solutions to decarbonizing logistics.

When regional road haulage interests advocate for keeping higher speeds on city streets, and resist reallocation of space to cyclelanes, they are not serving city-based businesses. Indeed, their position is unethical, harming children – particularly – in multiple ways.

Cycling, Skateboards, Scooters

The space provided in the streetscapes above will allow for radically improved safety, encouraging people of all ages to shift from driving to cycling, scootering or skateboarding.

Here’s an excellent video about designing safe bike lanes:

A word about the Back-Streets Fantasy

People often suggest a “back-streets network” is all that’s required – typically for cycling, but sometimes even for safe walking and safe wheelchair use, too.

But relegating these travellers to the back streets doesn’t meet their needs. None of these streets that bound the low traffic neighbourhoods below, for example, have a valid back-street parallel option:

Cyclelanes belong on Auckland’s arterials, where wayfinding becomes intuitive, and routes are direct. This is because the majority of people are interested in cycling, but concerned about safety:

People need to be kept safe all the way to their destination. Within the Low Traffic Neighbourhoods, there are streets where vehicle traffic volumes and speeds are both so low that it is possible for bikes to mix with cars. But every arterial needs protected cyclelanes, or the majority of people won’t cycle.

The “back-streets” suggestion stems from a resistance to taking space from public transport, freight or general traffic. The argument is counterproductive for those networks, though, because without door-to-door safety for walking and cycling, congestion won’t drop:

• Deliveries would still be by courier van, not cargo bike
• Children wouldn’t be able to cycle themselves, they’d still be driven
• Adults would drive too, as walking or cycling on unsafe roads wouldn’t be attractive.

Back-streets are great places to walk and cycle – if that’s where you’re going. Some complete off-street paths would also be great in addition to the streets. But off-street and backstreet routes are insufficiently connected, direct or intuitive to create a network.

Paradigm Shift

At the beginning of the post, I asked you to imagine reducing traffic considerably, and then tried to paint a picture of how our streets could be if we managed to do so.

But throughout the post, you may have realised that it is through transforming the streetscapes that people can stop driving. By giving space to the space-efficient modes – like walking and cycling – we give people options, reducing car traffic.

We ALSO increase capacity. There are lots of different versions of this diagram, using different values. This is Auckland Transport’s version:

Reducing the number of general traffic lanes allows us to re-establish the missing network of safe cycling. This is critical for our growing city, to increase capacity and give people freedom of movement.

Liveable arterials can be delivered using a tactical approach, moving kerbs and drains as little as possible. A city-wide approach can use economies of scale and be delivered cheaply. The approach makes better use of our infrastructure, lowers our transport costs significantly over time, and delivers better on our existing challenges.

But it does require a major paradigm shift, which focuses on delivering accessibility, liveability and freedom, rather than high vehicle throughput.

Postscript

I named this post after the subject of a presentation to the 9th International Cities, Town Centre and Communities Conference in Sydney in October 2008. The conference programme says:

Liveable Arterials in Auckland City – the Challenge and the Process (p42) Mr Ian Munro, Urbanismplus Ltd & Mr Matthew Rednall, Auckland City Council, Auckland, NEW ZEALAND

Auckland City Councillors were advised the conference was:

an opportunity for Council representatives to gain an increased understanding of best practice in sustainable development, town centre revitalisation and public space redevelopment.

There have been different names for the work since: the Corridor Management Plan, Integrated Corridors, and now Connected Communities.

But thirteen years on, what has been delivered? Who’s in charge? And who’s keeping watch?

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