Tag Archives: complete streets

Passive vs. Proactive Design

Greeley

Each weekday nearly 300,000 Portlanders take to the streets as they make their way to work, and most of them are driving. Despite the city’s mostly successful efforts to promote public transit and active transportation, most commuters still prefer the convenience of their own cars.

MODE COUNT PERCENT
DROVE ALONE 180,107 64%
CARPOOL 25,736 9%
TRANSIT 34,289 12%
BIKE 18,912 7%
WALK 21,336 8%
OTHER 3,247 1%
TOTAL 283,627

 

This isn’t a revelation. We know that Americans rely on driving to get where they need to go. This preference has shaped our communities for almost two hundred years and defines many of the habits of our everyday lives. As an example, my family and I live about one mile from the nearest grocery store and without much trouble or effort could walk there every day or every other day to buy what we need. It is much more convenient though to make the trip once a week, and while I can walk to the store in about fifteen minutes, what I can’t do is carry a week’s worth of food back with me. Isn’t it great that we have a car to help us with that!

To go further, every aspect of the typical supermarket grocery store – from the size of the carts to the size of the parking lot – is designed to support the weekly shopping trip. This is just one piece of our car centered culture. During my one mile drive to the store, I also pass three gas stations, three auto parts stores and two rental car agencies. If I’m willing to make an extra fifteen minute commitment, my options open up to several more stores that might offer better selection, lower prices or both. None of this surprises you, of course, because this is normal to us and normal things aren’t usually that surprising. There is a good chance that my routine is not that different from your own.

There is no community in the United States that isn’t in some way designed around cars. Cars affect every place and every moment of our lives. As our reliance on them has grown, so too has our need for safe streets. To this end, engineers determine street widths, speed limits and a host of other factors according to well established guidelines with the goal of preventing cars from crashing into each other as they move from place to place. While this framework for design has been intentionally evolved over time, many of its effects on our communities have not.

As traffic speed increases, so does the frequency and severity of traffic accidents. Research tells us this, and we expect it from our own driving experience – so, we each limit our speed to our own comfort range. The street’s designers are also trying to manipulate this range to what they feel is safe not only through posted speed limits, but also with more subtle traffic calming measures like lane widths, lane configurations, curve radii and building setbacks. Your driving speed, then, is controlled by two factors: it is directly controlled by how fast you are comfortable driving and indirectly controlled by how fast the designers would like you to be comfortable driving.

The sometimes ignored aspect of this conversation is that there is a reciprocal relationship between these factors. Imagine I am designing a street through an already developed part of your town. I want to understand how the road can better serve your community, so I perform a traffic study to determine how people use the existing street and how that relates to transportation in the surrounding area. From this study, I learn that while the posted speed limit is 25 mph, most people drive closer to 35 mph. This is a big difference and represents a decision point for my design. I want to create a street that is safe for the people who use it, but I also want to create a street that encourages people to use it safely. There are two general approaches that I can take from here.

Approach 1 – Passive Design

Seeing the discrepancy between posted and actual speeds, I have decided that while the street’s classification doesn’t warrant raising the speed limit, it is prudent to design the road to accommodate traffic travelling at a higher speed. Having made this decision, I use some of my available right of way to provide slightly wider lanes. I also lengthen the curves along my corridor to increase how far up the road you can see and give you more time to make decisions while you are driving. Finally, I provide moderately more protection for both drivers and pedestrians by setting street trees and sidewalks away from the edge of the road.

This is of course oversimplified, but the decision making process that I have followed is very reasonable. Each design choice was made to better protect you – the citizen, tax payer and user – based on my understanding of how you drive. The problem is that space in the right of way is limited. Each of my decisions came with a trade off, and because my approach was entirely vehicle-centric, I prioritized driver safety over other street uses at every step. I gave you slightly wider driving lanes so you have room to safely travel at your desired speed. This likely meant making a choice like building narrower bike lanes, leaving cyclists with less room to travel. I set the streetscape features and sidewalks away from the road so they would be less likely to obstruct your driving. This likely left less width for sidewalk and other pedestrian facilities.

Approach 1 has been dubbed “passive design”, a term that is not generally used in a good way. By focusing solely on vehicle needs and safety, we provide less room for cyclists and walkers. We are then encouraging or at least accommodating higher speeds in closer proximity to the street’s most vulnerable users, who are forced to use less robust facilities. At the very least this presents a serious safety concern. At the most it discourages people from using the street for anything other than driving a car. There has to be a better approach to designing streets that accommodate multiple uses, and fortunately there is.

Approach 2 – Proactive Design

Seeing the discrepancy between posted and actual speeds and deciding that the street’s classification doesn’t warrant increasing the speed limit and understanding the goals for the area, I have decided that something must be done to discourage speeding. I create lanes that will still accommodate traffic, but will also feel tighter to drivers, encouraging them to slow down and drive more precisely. Having chosen the lower posted speed for my design, I can bring streetscape features closer to the curb line, reinforcing the narrower feel. Right of way width is also less of an issue now and I can include safer, more generous bike lanes and sidewalks, making the street a more attractive corridor for active transportation.

By creating a safe environment for cyclists, pedestrians and other non-vehicular users, we build on our goal of creating streets that better serve our communities. By encouraging more people to use active transportation options and by giving them safe places to ride and walk, we create new growth opportunities and bring a different type activity to business corridors. The service for car traffic is still there, but the newly imagined street can also be so much more. From public health to business development to transportation, proactively designed complete streets are an important component of strong communities.

None of this is meant to suggest that we can avoid difficult design decisions by being proactive. If there were no difficult design decisions, there wouldn’t need to be engineers to help make those decisions. But our long term visions for how we would like our communities to grow and thrive are fragile things. Civil works projects represent great opportunities to strengthen these visions, as they focus on bringing some kind of change. These opportunities are lost, though, if we stop at passively identifying and accommodating existing uses. By proactively reviewing these uses against long term goals, we still allow ourselves to take the steps needed to maintain our infrastructure, but we also capitalize on a rare opportunity to strengthen and build our communities.

How have passive and proactive approaches affected development in your community? I would love to hear your stories and encourage you to leave them in the comments section below.

[From photo above] The design of Greeley Avenue in North Portland attempts to balance the needs of passenger car, freight, transit, cyclist and pedestrian users, all on a relatively high speed road. With the high projected growth, the City is developing proactive designs that would significantly change traffic patterns here, including a greenway trail along the Willamette River that would move cyclists and pedestrians off the road.