Radburn design

In my last post, I wrote about how connected roads make our communities safer.

Connected roads also reduce the time we spend in cars, which provide large but overlooked traffic safety benefits.

This may seem counterintuitive because much of traffic safety planning has, for decades, revolved around reducing risky behavior: teens get graduated licenses, we have distracted driving campaigns.

The newer safety paradigm revolves around making the entire transportation system safer. That means thinking about complete streets, multi-modal transportation planning, and creating neighborhoods and communities that involve fewer hours in cars.

The less time we spend in cars, the safer we are

All else being equal, the single most beneficial thing that can be done to improve road safety is to reduce the total number of miles people travel in vehicles. A review of literature related to vehicle-miles traveled (VMT) shows that collisions and deaths increase the more VMT increases. (So, too, do emissions.)

This is why the planned Chapel Hill Connector roads policy is so exciting to me. The Town of Chapel Hill is pursuing a policy where new developments will be connected – both improving connectivity and improving safety.

But in Carrboro, where I live, we still have a long way to go. Carrboro does have a connected roads policy, last updated in 2005 – you can read it here – but it’s not always followed. Many of the neighborhoods in North Carrboro, where I live, are not connected and require us to take long, convoluted paths to leave the neighborhood or get over to the next neighborhood.

Why connected roads reduce VMTs

Connected roads – which are typically a grid system –  allow multiple ways in and out of a neighborhood. This decreases the total amount of time a person travels in a car, decreases the total amount of time delivery and municipal trucks are in neighborhoods, and reduces or eliminates the need for these large trucks to back-up. (25% of accidents happen while a vehicle is backing up, but a vehicle is only backing up <1% of the time)

Grids with a number of intersections naturally encourage drivers to drive more slowly, more cautiously and be more alert overall. If you eliminate the long, straight, wide ‘collector’ roads in neighborhoods, which many cul-de-sacs and lollipop streets feed into, you decrease drivers, pedestrians and cyclists’ exposure to vehicles overall.

This grid layout works exceptionally well in tandem with mixed-use zoning interspersed amongst residential homes. The current zoning method which places the services many people need daily outside the distance of driving or walking makes everyone drive longer. But corner stores and corner coffee shops, which were once ubiquitous in neighborhoods all across the US, allow people to grab a coffee or milk without needing to get into a car – and they also create third spaces where communities can flourish and hang out. (Imagine this in Carrboro! Or this!)

Connections reduce sprawl

Reducing sprawl and making neighborhoods more connected makes them safer. Drivers go faster when they’re funneled onto a smaller number of larger, faster roads like the many that connect existing cul-de-sacs across our towns.

I hope that developers, the Town of Chapel Hill and the Town of Carrboro will continue to emphasize the importance of connected roads and the power of the street grid in reducing the amount of time spent in cars, which will help make all the roads of these towns safer.

Brian Crawford lives in Carrboro with his wife and two kids. He has a Masters in Data Science and enjoys using data to help make the world a better place. He believes in creating strong towns, with complete...