How Millennials Will Shape the Future of Complete Streets

by Sheldon S. Ah Sing, AICP, Principal Planner at M-Group

Washington DC, I Street  (source:

Washington DC, I Street (source:


Complete streets are streets designed to accommodate all users, of all ages and abilities, and implementation of complete streets have provided a number of benefits within the community. In the past, the primary emphasis in street design was on the speedy movement of motorized vehicles along the right-of-way. The complete streets idea is based on the concept that a balanced, multi-modal transportation network would make the most efficient use of transportation infrastructure, serve to reduce greenhouse gas emissions and improve public health by encouraging physical activity through shifting short trips from driving to biking, walking and public transit. Since the implementation of complete streets, in addition to promoting healthy communities, it has also been found that complete streets have the effect of supporting local businesses and encouraging economic development. Communities have realized that implementing complete streets that foster multi-modal activities such as walking, bicycling and transit usage provide a wide range of benefits to employees, visitors and residents that make their community a desirable place to work, visit and live.

Millennials, the generation generally categorized as being born in a timeframe between the late 70s and 2000, grew to a population of 78.6 million in 2010, surpassing baby boomers as the largest demographic cohort in U.S. history. This generation’s preferences are changing the way products are advertised and how they are consumed and their lifestyle preferences are changing the way built environments are developed.

This article summarizes the benefits of complete streets, the importance of public investment in complete streets to spur private investment and the importance of thinking beyond downtowns and implementing complete streets in suburbia to account for the trends of millennials, the emerging demographic cohort entering the housing market.


Complete Streets Approach

The National Complete Streets Coalition states that “Complete Streets are streets for everyone”. Effective planning for complete streets balances allocation of space within the right-of-way to provide safe and effective infrastructure that can be used by all transportation modes and users. Effective complete streets empower users of all ages and abilities to safely move along and across streets in a community. By planning for a broad population, the approach brings together advocates and stakeholders from many different interest groups including older people, public health agencies, transportation engineers, bicycling and walking advocates, local business supporters and other interested people. Furthermore, complete streets policies can be written to support a broad range of community goals.

Seattle, WA (before and after)  (source: Smart Growth America (March 2013): Safer Streets, Stronger Economies: Complete Streets project outcomes from across the country)

Seattle, WA (before and after) (source: Smart Growth America (March 2013): Safer Streets, Stronger Economies: Complete Streets project outcomes from across the country)

Typical complete streets improvements include:

  • Narrow travel lanes and seek opportunities to put streets on a road diet. For example, the conversion of a four-lane undivided road to a three-lane road with bike lanes (two-way left-turn center lane, two automobile travel lanes, and two bike lanes). This configuration can handle up to 18,000 Average Daily Trips (ADT) and improves safety and access to adjacent destinations.
  • Tighten corner curb radii to the minimum needed to provide a usable turning radius for an appropriately selected design vehicle. Occasional encroachment by larger vehicles into other travel lanes is acceptable; intersections should not be designed for the largest occasional vehicle.
  • Eliminate unnecessary turn lanes at intersections. Eliminating free-turning right turns or right turn lanes with fewer than 100 turns per hour.
  • Replace painted channelization islands at intersections with raised islands. This gives pedestrians a true place of refuge and breaks up long crossing of many lanes into smaller segments.


California Context

In 2008, the State of California adopted the California Complete Streets Act that required cities and counties to incorporate complete streets policies within their circulation elements upon any substantive revision to the general plan element. Complete streets policies plan for a balanced, multi-modal transportation network that meets the needs of all users of the streets, roads and highways, defined to include motorists, pedestrians, bicyclist, children, persons with disabilities, seniors, movers of commercial goods, and users of public transportation, in a manner that is suitable to the rural, suburban or urban context of the general plan.


Benefits of Complete Streets

A study by Smart Growth America published in 2015 reviewed 37 complete streets projects across 31 cities in 18 states and summarized the benefits of investing in complete streets projects. While limited in data and far from conclusive, the case study points to some very encouraging themes. It showed that complete streets projects improved safety, increased biking and walking, and resulted in mixed outcomes regarding increased and decreased vehicular traffic depending on the project goals.  In part, this mixed-result is because of differing methodologies employed in gathering the data, however, nonetheless, based on the available before-and-after data, regardless of vehicular information other key indicators had positive correlation with complete streets resulting in benefits.

Implementing complete streets can alleviate the problems created by existing auto-oriented streets. Auto-oriented streets are less safe because of higher speed limits, large widths, and inadequate sidewalks and crosswalks.  The case study demonstrated that decreasing the number of lanes and adding crosswalks, bike lanes and a center turn lane can result in reduced speeding, collisions and injuries. The same study indicated that in most instances pedestrian activity increased along with bicycle trips. Complete streets projects have also shown to have a mostly positive increase on public transit use. Walking is the most common way to access public transit and complete streets strategies can be used to complete the last mile on either end of the transit trip. Complete streets help create environments that led to increases in walking, biking, and transit use.

Local businesses see many benefits in improving access to people traveling by foot or bicycle. When a bike lane was added along Valencia Street in San Francisco’s Mission district, nearby businesses saw sales increase by 60 percent, which merchants attributed to increased pedestrian and bicycle activity (Smart Growth America, Complete Streets Spark Economic Revitalization).


Funding and Role of Public Investment

The hallmark of complete streets projects is that the project uses the existing right of way. There are no acquisition costs, and the typical improvements for complete streets is minimal. Complete streets projects cost less than conventional roadway improvement projects. On average a complete streets project costs $2.1 million (Smart Growth America, Safer Streets, Stronger Economies). These projects also cost less per mile than average arterial roadway projects. The Federal Highway Administration estimates that construction of an average “normal-cost” urban arterial costs $3.58 million per mile, and average “high-cost” arterials cost $12.75 million per mile.

In the mid-90s, the City of Portland spent $60 million and built 300-miles of bicycle infrastructure (lanes, paths and boulevards). For this modest investment, between 1990 and 2008, bicycle trips increased by 400 percent, while driving alone decreased by four percent and there were no bicycle fatalities. For the same investment, the City could have constructed one mile of a four-lane freeway. The results in Portland suggest that a fractional investment can lead to changes in travel behavior and safety.

Implementing complete streets projects can leverage future funding opportunities, since multi-modal projects are more competitive than singular-modal projects.

Public spending can spur private development

The investment that communities make in implementing Complete Streets policies can stimulate far greater private investment, especially in retail districts and downtowns where pedestrians and cyclists feel unwelcome. In Washington, D.C., design improvements along a three-quarter mile corridor in Barracks Row, including new patterned sidewalks and traffic signals, helped attract 40

new businesses and nearly 200 new jobs. The area experienced increases in sales and foot traffic. In Mountain View, California, the addition of space for sidewalk cafes and a redesign of the street for pedestrians were followed by private investment of $150 million, including residential, retail and offices, resulting in a vibrant downtown destination.  This provides evidence that the street and the land use work together and determine whether a place is attractive and draws people and investment and high-quality land uses come to high-quality streets.


Suburbia and Millennials

A desire for more walkable environments is growing among the younger population seeking housing opportunities. Millennials, the generation generally categorized as being born in a timeframe between the late 70s and 2000, grew to a population of 78.6 million in 2010, surpassing baby boomers as the largest demographic cohort in U.S. history. The idea of millennials living mostly in amenity-rich apartments in downtowns is not completely accurate. An Urban Land Institute report found that many millennials are living in less centrally-located but more affordable neighborhoods and sharing space with parents or roommates to save money. In summary this study found that:

  • Only 13 percent of millennials live in or near downtowns; 63 percent live in other city neighborhoods or in the suburbs.
  • Fifty percent are renters, paying a median monthly rent of $925.
  • Twenty-one percent live at home, but 90 percent expect to move out within five years.
  • Fourteen percent live in households with three generations of family members.
  • Eighteen percent of all millennials and 27 percent who rent share housing with roommates. However, 58 percent of those with roommates would prefer to live alone.
  • Virtually all expect to own a home eventually.
  • Nine out of ten expect to match or exceed their parents’ economic circumstances.

According to the study, “millennials expressed a higher level of dissatisfaction with their communities and local housing options than did [people in] other demographics”. Moreover, the study continues “they say that neighborhoods lack convenient outdoor spaces to run, walk, bike, and exercise. In addition, they believe that both traffic and crime make it unsafe to walk.” More than 60 percent of millennials, want to live in areas where they can use their cars less.

The preference for walkable neighborhoods is likely to increase in coming decades, too, as today’s young college graduates flock to downtowns and close-in suburbs. The population of college-educated 25 to 34 year olds in these walkable neighborhoods has increased by 26% in the last decade, creating a workforce that can further add to economic growth in these communities (ibid).

This cohort will eventually marry and have a family then seek housing appropriate for that lifestyle. Downtown living is expensive and unaffordable and suburbs alternatively provide the type of housing and affordable that would match the desires of millennials in the future. Whether they are in downtowns or in the suburbs, there will be a demand for more walkable places.


Much of suburbia will have to change in order to thrive and meet the health, environmental, and economic challenges of the coming decades. Because of their form, widely separated land uses, and disconnected street networks, most suburban areas lack walkability and require that people travel by car for most of their needs. Demand from millennial preferences are making it desirable to retrofit these communities with complete streets to meet the needs of the changing demographics.

The primary challenge in retrofitting suburbia is less fixing the infrastructure and more creating economically sustainable places, with the emphasis on place.  Not only streets will need to change in suburbia; many land uses are obsolete and/or no longer economically viable. Street improvements generally should come before land use change in suburban retrofitting. This is because high-quality land uses come to high-quality streets and that generally means more economic benefits. The street and the land use work together determining what is attractive and draws people and investment. The following should be considered when retrofitting suburbs:

  • Focus new investment in nodes on streets. There will not be enough investment all at once to transform entire corridors.
  • Focus revitalization efforts on creating genuine places in those nodes: compact, mixed-use, transit-oriented, and at least internally walkable. Plan for and enable neighborhood-serving commercial districts rather than automobile-serving uses.
  • Carefully detail the desired outcomes. It is important that retrofit efforts follow through desired outcomes such as reduced vehicle miles travelled, reduced greenhouse gas emissions and increased transit and bicycle ridership. 
Simulation of Suburban Street Transformation  (Source:

Simulation of Suburban Street Transformation (Source:


The complete streets concept provides an economically effective way to improve health, economic development, transportation efficiency and safety for communities. It has been proven that complete streets work in urban downtown areas. The same complete streets principals can be used to retrofit suburban infrastructure. This would be necessary to accommodate the future demands of housing for the next generation.



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