A stroad is a thoroughfare that combines the features of streets and roads. Common in the United States and Canada, stroads are wide arterials that also provide access to strip malls, drive-throughs, and other automobile-oriented businesses.
Stroads have been criticized by urban planners for safety issues and for inefficiencies. While streets serve as destinations and provide access to shops and residences at safe traffic speeds, roads serve as high-speed connections that efficiently move traffic at high volume, and stroads attempt to serve both purposes. Critics argue they are often an expensive, inefficient, and dangerous compromise.
Term
Etymology The word "stroad" is a portmanteau of the words street and road. It was coined in 2011 by civil engineer and urban planner Charles Marohn to describe what he considered failures in North American infrastructure development. The concept was popularized in April 2021 through a short documentary published by the urban planning YouTube channel Not Just Bikes.
Definition
A stroad is a thoroughfare which tries to serve pedestrian and vehicular traffic simultaneously, but does neither effectively. This is defined in contrast to a safely-accessible street that prioritizes pedestrians or a high-throughput road that prioritizes vehicles.
Mahron describes a street as "complex environment where life in the city happens". Streets are lined with buildings, such as houses, stores, and offices, whose entrances and exits open onto the street. As such, streets must accommodate both cars and pedestrians, through-traffic and entrances/exits from adjacent buildings, and temporary parking and delivery vehicles. As this complexity greatly increases the risk of accidents, an ideal street will have low speed limits, enforced by traffic calming features such as narrow lanes.
Conversely, Mahron describes roads as a "high-speed connection between two places". To mitigate traffic and reduce the risk of accidents, an ideal road will have limited entrances and exits, no parking, and strict segregation of vehicular and pedestrian traffic. They also have wide lanes, and are designed to run as straight as possible, only making gentle curves where necessary.
As stroads attempt to function as both a street and road, they will often combine features of both. Like a street, stroads are lined with buildings whose entrances and exits open directly onto the stroad. However, like a road, stroads permit vehicles to travel at high speeds, and will have wide lanes and be generally straight to accommodate them. In essence Marohn defines a stroad as a high-speed road with many turnoffs, and lacking in safety features.
History
Stroads began to emerge in the United States and Canada in the aftermath of World War II, as car ownership became widespread and suburbanization accelerated.
Some stroads were created when streets were expanded or widened, often with the aim of improving mobility. This was often done without proper access management, and under the influence of engineering codes that emphasized speed and traffic flow over safety, resulting in the street becoming a stroad. Other stroads were created when developers began adding private accessways onto roads. As the number of accessways increased, so did congestion and collisions on the road, requiring traffic control additions such as traffic signals.
Dutch urban planner Willem Zurborg argues that this conversion of streets and roads into stroads was a consequence of local governments designing their roadways to serve as flow roads, distributor roads, and access roads (i.e., streets) simultaneously. Dover and Massengale make a similar argument, noting that the general public is often not aware of the functional distinction that engineers make between streets and roads. In the English-speaking world, street names often end with 'road' and vice versa due to historical reasons; this may be misleading and not align with the current de facto traffic situation.
Disadvantages Safety risks By combining the high speeds of roads with the complexity of streets, stroads put both pedestrians and drivers at elevated risk. A 2021 report by the Governors Highway Safety Association found that 60.4% of pedestrian fatalities from motor vehicles in the United States occurred on stroads.
Dangerously high speeds
The design of stroads encourages motorists to drive at dangerously fast speeds. Vision Zero Coalition's 2018 report explains that the wide lanes and lack of sharp turns in stroad design give drivers a false sense of safety, which subconsciously encourages them to drive at dangerously fast speeds. Stroads in the United States and Canada typically have legal speed limits between . But since the design speed is much higher, motorists frequently drive at up to . Therefore, reducing the posted speed limit (PSL) with a traffic sign, a widely adopted strategy, will not work. "If the road [design] ... suggest[s] that the PSL is too low, drivers may simply ignore it".
This is a problem because the frequent entries and exits onto stroads create many points of conflict and potential collisions for drivers to navigate. Driving at higher speeds reduces the time drivers have to react to hazards, increasing the risk of a crash. It also means any collision will have a much higher kinetic energy, increasing its severity.
Lack of protection for pedestrians
The quality of sidewalks next to stroads is often poor. Many stroads do not feature any sidewalks at all. In the case of stroad-like suburban residential streets, sidewalks are sometimes deliberately left out by design in order "to further the rural image". Sometimes there are only "painted sidewalks" next to a strip mall, without curbs or traffic bollards to protect pedestrians against vehicles that may deviate from the road. Stroads also often lack other pedestrian safety features, such as crosswalks and adequate street lights.
At intersecting stroads, vehicles often need to decelerate from a high to a low speed to make a sharp turn right from a long turn lane parallel to the sidewalk; this makes walking there particularly dangerous for pedestrians. Sidewalks are sometimes too narrow, feature many obstructions such as street lights, as well as driveway cuts, which make them pedestrian-unfriendly. These obstacles may force pedstrians off the sidewalk and onto the edge of the stroad, putting them at further risk.
Marohn argues that a person on a sidewalk has no defense at all if a vehicle leaves the roadway at stroad speeds. He points out that traffic lights, such as those next to the State Street stroad in Springfield, Massachusetts, are often designed with shear pins at the base so as to break off if a vehicle happens to crash into it. Although this design increases the safety of the driver and any passengers, it also significantly decreases the safety of any pedestrians who may be standing or walking on the sidewalk behind the traffic signal. Marohn was astonished to discover that a bench had been placed right next to this breakaway traffic light pole, "inviting people to sit in a place where the chance of a driver losing control and going off the roadway at high speeds is so great that the city installed breakaway poles."
Increased congestion
Stroads are often billed as a way to make traveling by car more efficient; however, this is not always the case. Despite the high speeds that stroads were designed for, in practice they frequently end up being clogged with cars seeking access from the many entrances. As a result, the average speeds on stroads are low due to traffic congestion. Widening stroads to counter congestion usually only leads to induced demand and extra costs.
Low return on investment
Poor mix of street and road functions
In his commentary, Marohn states that stroads do not function well as either a street or a road. By trying to be "all things to all people", stroads end up failing at the functions of both.
Dover and Massengale (2014) state that the design of roads was originally modeled on the railroad, as they were intended to serve the same function: namely, providing an efficient connection between two populated places, such as cities, towns, or villages. Streets, on the other hand, formed networks within a single place to facilitate travel within their boundaries. They argue that two systems functioned well as long as they remained separate, resulting in increased financial productivity in the region they served. However, they warn that "we reconfigure our streets to have the characteristics of roads—as stroads—we are no longer able to capture the value of shar[ing] the space."
Jason Slaughter, of the urban planning YouTube channel Not Just Bikes, points out that when the Netherlands implemented clear functional distinctions between motorways (highways), roads, and streets in the 1990s, it led to increased safety, traffic flow, and cost-effectiveness, while also reducing car dependency and increasing walkability, cyclability, and overall livability. The change resulted in a 30% decrease in expected traffic deaths between 1998 and 2007. Slaughter points to this difference in outcomes to argue that North American stroads are "inefficient", as well as ugly, dangerous, and more expensive.
Infrastructure costs Marohn (2017) stated that stroads "are enormously expensive to build and, ultimately, financially unproductive". This is because "stroads are built to a highway standard, their lanes are very wide, and there are never [fewer] than four lanes", or "at least three through lanes", and they usually take up extra space for shoulders and clear zones. Stroads feature many more entrances and exits than limited-access highways and roads and thus require more turning lanes, and because stroad vehicle speeds may be higher than on a street, the turning lanes are much longer to allow vehicles to decelerate and reduce the risk of rear-end collisions; this means stroads require more and longer turning lanes, which are more expensive to build and maintain and take up more space than streets and roads do. The high frequency of accesses to a stroad with much traffic often prompts the construction of traffic lights at intersections, which may cost up to $250,000 to build (excluding maintenance costs).
An extreme example of this is at the intersection of Charleston Boulevard and Decatur Boulevard in Las Vegas, which features seven approach lanes, each with traffic lights. The larger size of stroads compared to streets and roads means they require more space which needs to be purchased, flattened, and asphalted, which reduces the property value of the land, increases the cost of flood protection infrastructure, and adds regular asphalt and traffic control system maintenance costs. Compared to households along urban streets, stroads tend to double the costs that households pay on the construction and maintenance of infrastructure, as well as the delivery of public services, while the tax revenues per acre of properties along stroads are lower compared to urban commercial streets.
The space taken up by stroads, as well as the large areas dedicated to parking lots at the destinations of cars using stroads, result in low-density land use (typical for urban sprawl). This makes stroad environments significantly less productive and tax-generating than streets, but with significantly more infrastructure and thus higher per-area maintenance costs, so that they become a net negative and a financial burden for cities, and they cannot therefore sustain themselves.
Aesthetic and quality of life concerns