BY WILLIAM R. SAGER
“You can’t get there from here; you have to go around” is a truism that describes how difficult it is to get from one location to another. In many emerging suburban communities, this old saying rings especially true for the fire service. In newer communities, the impact of street design and circulation patterns on increasing response times is dramatic. Because of design pressures on planners to make pedestrian-friendly communities, some communities now have to develop additional fire stations to provide adequate response time coverage based on best practices such as those found in National Fire Protection Association (NFPA) 1710, Standard for the Organization and Deployment of Fire Suppression Operations, Emergency Medical Operations, and Special Operations to the Public by Career Fire Departments, or shortchange some neighborhoods with less than satisfactory response times. In addition to the strategic implications of street design, there also are many operational considerations affecting fire unit and ambulance response, apparatus types used, and maneuverability.
Traffic congestion in the larger cities and more built-up areas of the country is already affecting fire departments’ ability to respond effectively and in a timely manner. Communities need to carefully consider how developing road networks that work against emergency responders’ needs may add to this misery.
Traditional cities used a grid pattern to lay out the streets. Dead ends, curvilinear streets, sound walls, and traffic-calming devices are just a few of the contemporary circulation impacts on emergency response. Not satisfied to see the emerging suburban communities endorse these concepts, older cities often now retrofit some of these aspects of design in older neighborhoods.
The intent of reducing traffic for those living on these streets is a noble one, but the impact on emergency response can be profound. For example, fire department experiments have found that, on average, one traffic-calming device (e.g., a speed bump or traffic circle) adds 10 seconds to response time. Thus, if on a given response an emergency unit encounters six devices, one minute is lost. This can be significant if the fire stations are already spaced at the maximum distance or too far apart.
The basis of fire department deployment, simply stated, is about the speed and weight of the attack. Speed requires that first-due, all-risk intervention units (engines, trucks, and ambulance companies) be strategically located across a department’s response area. We call this concept distribution. NFPA 1710 suggests four minutes or less for the driving part of response time of the first-arriving engine. If a community chose to accept this criterion, the system design would call for the equitable distribution of fire stations approximately eight minutes apart.
Weight considers a multiple-unit response for significant emergencies such as a room-and-contents structure fire, a multiple-patient incident, a vehicle accident requiring extrication, or a heavy rescue incident. NFPA 1710 suggests eight minutes or less driving time to assemble enough firefighters in a reasonable period to control the emergency safely without its escalating to greater alarms. If a community chose to accept this criterion, the system design would call for the appropriate concentration of fire stations to be approximately eight minutes apart or less. In other words, both distribution and concentration rely on a road network that expedites rapid response into neighborhoods.
What are these impediments to circulation, and what can the fire service do about them? The design and layout of circulation does not arise by accident. The engineering involved is straightforward but does require a civil engineering degree, field surveys that measure the lay of the land, accurate estimates of traffic flow, adherence to local standards, and meeting the community’s planning requirements. Most engineering firms today use computerized models of traffic flow to develop adequate roadways in new neighborhoods.
Although land developers do not design circulation patterns to impede emergency response, the rapid sale of new homes and commercial properties is the compelling issue for them. Consequently, they have their engineers design what they believe the market demands and seldom consider efficient routes for emergency response, trash collection, street sweeping, or large delivery trucks in the design.
Analogous to street circulation patterns is the typical hydrant system. The same elements that make a hydrant system work wella good grid, adequate pumps, and large mainsare the same elements that make a street system work well for emergency response. Fire departments are generally very conscientious about the hydrant system’s design; but they frequently fail to consider the layout of streets that connect the fire stations to the neighborhoods.
CIRCULATION DESIGN ELEMENTS
To better understand the way engineers design street systems, chiefs need to understand their unique terminology and the impact that some of the design elements have on rapid emergency response. Typical suburban street design includes a hierarchy of streets. It has a tree-like or “dendrite” pattern that starts out from the cul-de-sacs, then to the local streets, then to a secondary road system called “collectors,” and finally to the primary road system called the “main arterials.”
“The hierarchal street layout reflects the guiding principle that streets on which residences front should serve the least traffic possible. At best, only vehicles traveling to or from the homes on a given street would ever appear on that street …. Traffic from residential streets is quickly channeled through the street hierarchy to collectors and then to arterials. Only arterials … provide connectivity between land uses and other neighborhoods.”1
Dead-end streets (cul-de-sacs).Everyone wants to live on a dead-end street; there is little traffic, children can safely play in the street, the street is quiet, and neighbors can easily get together. The dead-end street, or the more contemporary term cul-de-sac, is ideal for property sales. As a result, developers will want to maximize the number of dead-end streets.
For the fire service, dead-end streets mean less connectivity. In addition to its impact on circulation, the dead-end street affects operations as well. Often, only one or two pieces of apparatus can get close to the buildings at the end. If several apparatus respond, they will stack up, making it difficult to extract one piece of apparatus. Truck placement is more complicated, and firefighters often have to lug hose and equipment longer distances. As with water main design, neighborhood street design should avoid dead ends. More dangerous is the effect of long dead ends on wildland fire operations. While many fire units from one direction are approaching and positioning to defend the neighborhood’s edge at the dead end, the police and citizens are moving in the opposite direction to evacuate the area. Chaos can result, and neither the fire attack nor the evacuation succeeds.
Local streets.Cul-de-sacs need to connect to something so that people can get to the world outside of the local neighborhood. In modern street design, local streets are generally not too long, since developers want them to be quiet roads like the cul-de-sac to encourage more home sales. Local streets are the same width as the cul-de-sacs and designed with the same curb, sidewalk, setback, parking, and lighting standards. If the street design connects local streets in a grid fashion, responding apparatus will have a number of response options. The ability to work around traffic or access difficulties using alternate routes increases the street network’s reliability. As with the gridded water main that provides water to both sides of the hydrant, the gridded street system allows units to respond from both directions.
Sadly, the local streets often are not part of a true grid network. Instead, all too often, we see the street named, “Such and Such Circle,” indicating that the local street loops around from the collector back to the collector with any number of cul-de-sacs and perhaps another circle branching off of it. Some contemporary designs in fact have circles inside of circles. Other designs have a series of circles that alternate on both sides of the collector in a serpentine fashion. In such networks, connectivity is at best difficult and often impossible until the driver returns to the collector.
One of the operational problems with the circuitous design of these local streets is that orientation is very difficult. As the street curves, what started out as a north-south orientation can become an east-west and then south-north direction on the same local street. In such a design, if the driver/operator makes a mistake and turns onto the wrong circle, he may not be able to correct the error until he returns to the collector. With a grid system that is easy to memorize and visualize, course correction is easier.
Collectors.Collectors, the next level in the street hierarchy, collect the traffic from the local streets. Their design should balance mobility and land access within the community’s residential, commercial, or industrial area. They should accommodate the needs of pedestrians and bicyclists while also serving motor vehicles. In our water service analogy, collectors are like the secondary mains.
Collectors can be another trouble point. Because of the traffic, they are the least favorable places for people to live, so developers prefer to build the bare minimum number required. A minimum number of collectors means there are a minimum number of ways to enter or leave a given neighborhood. Redundancy and connectivity are once again sacrificed.
Although the typical speed limit on residential city streets is 25 miles per hour (mph), the limit on collectors can be higher, up to 35 mph. While these can be multilane, because they are collectors of traffic, congestion can reduce the speed advantage.
Arterials.The highest level road is the arterial, which carries large volumes of traffic across the city and from neighborhood to neighborhood. Arterials should provide a high degree of mobility and generally serve longer vehicle trips to, from, and within urban areas.
Arterials’ posted speed limits generally range between 30 and 45 mph. Usually the central business district arterials have the lower speed limits; speed limits are higher on arterials serving the outlying areas. In today’s world, an arterial street’s traffic volume and capacity often limit any advantage of higher speed limits for emergency vehicles.
Although this street hierarchy may satisfy developers and traffic engineers, it does not hold a candle to the traditional square grid for traffic capacity or emergency response. The traditional grid has a higher degree of connectivity and redundancy, both strong advantages for emergency response and fireground operations. “Fire departments and other emergency responders in older towns and cities are well-versed in working in traditional neighborhoods with narrower, tree-lined streets. They understand that while they may have to slow down a bit within the neighborhood, the well-connected street network and short blocks make it easier to find the property and give them more routes to get there. Many of these neighborhoods also have alleys or lanes that provide emergency responders with additional points of access.”2
Traffic circles (roundabouts). Many years of research from around the world have proven that traffic circles (also called rotaries or roundabouts) have 50 to 90 percent fewer traffic accidents than all other forms of traffic control. They are virtually maintenance-free, except for the landscaping. They allow a higher vehicle capacity than roads regulated by stop signs or traffic signals. They will slow traffic to less than 12 mph if designed well and may act as a gateway to communities and cities. Traffic circles reduce delays and pollution compared with other forms of traffic control. The modern traffic circle is smaller, safer, and slower and has a much higher vehicle capacity than older rotaries or roundabouts.3
Traffic circles slow down not only traffic but also fire apparatus. However, in today’s congested traffic situations, vehicles blocking apparatus do not have to wait for a green light to move out of the way.
Traffic signals.A traffic light is a signaling device positioned at a road intersection, pedestrian crossing, or other location to indicate when it is safe to drive through the intersection or walk across the street. Traffic signals do not separate vehicles physically; they merely control the time that a vehicle can occupy the intersection. They have a significant role in managing traffic in most communities. As a part of a coordinated traffic signal system, they can move significant volumes of traffic along major roads but they then delay drivers on side streets feeding into the major roads.
There are devices on the market that allow emergency vehicles to preempt the operation of traffic signals, forcing the signal to follow a sequence that opens the way for the emergency vehicle. Preemption devices should be in every fire departments arsenal for avoiding gridlock.
Center medians (neutral zones).Center medians provide beautification and traffic control. While beautification is important, as an element of urban design, traffic control interests us in this discussion. Striped center medians present few problems to responding fire apparatus. Center medians that are unpaved or have curves or collision barriers create a barrier for responding apparatus. If the barrier is long enough, responding units may have to pass an incident for as much as a quarter mile before they can conveniently and safely turn around and make entry to the target building. Retrofitted solid medians can also limit access to fire hydrants that were placed only on one side of the street.
Alleys.Older cities often have alleys, usually midblock, at the back of residences and commercial buildings. Alleys are service roads for garage access, coal and oil deliveries, trash pickup, and tradesman access. Alleys became associated with crime, developed a bad name, and fell from favor in the design of emerging suburban neighborhoods. About 20 years ago, architects and planners recognized that traditional neighborhoods incorporated many features that people found missing in the typical suburban design, hence the emergence of the “neotraditional neighborhood.”
The alley is one concept incorporated in the neotraditional neighborhood design. Primarily, this is designed to put garages back into the backyard and limit on-street parking and “snout” type garages. Reintroducing alleys to street design means that although neotraditional street design has a narrower standard, fire department access has less interference from parked cars, if on-street parking is limited or prevented. Also operationally, firefighters can use the alley to access the rear of the building.
Most neotraditional neighborhoods use a grid system that allows much easier access to the neighborhood for fire apparatus and ambulances.
Traffic-calming measures. Traffic-calming measures are physical barriers placed in the path of traffic to slow or divert the flow.4 They include vertical deflections such as speed bumps, speed tables, or raised intersections; horizontal shifts such as neighborhood traffic circles and chicanes (slight lane shifts to the right or left); and narrowed roadways such as chokers and center island narrowing. All these measures reduce speed and enhance the street environment for nonmotorists. They also include closures (diagonal diverters, half closures, full closures, and median barriers) to reduce cut-through traffic by obstructing traffic movements in one or more directions.
Traffic-calming devices are gaining popularity in older cities with traditional grid pattern streets. Moreover, the impact on fire apparatus response is the same as the roadway designs of emerging suburban communities. From a homeowner’s perspective, it is understandable to find less traffic desirable; unfortunately, the impact depends on emergency response into the area.
Railroad crossings.Although there is little the fire department can do to change the pattern of railroads through a community, crossings are an essential part of traffic discussion. The fire department should make every effort to ensure that construction of grade separated railroad crossings (overpasses) at strategic grade crossings are a priority in road construction funding. Not only do separated crossings save lives, but they also have a significant and positive impact on response times. If 30 trains a day pass through a community and each train blocks the road for a minimum of two minutes, for one hour out of every 24 that road is effectively closed. Railroad crossings should also be considered when planning the location of neighborhood fire stations. If there are no grade-separated crossings, it would be judicious planning to place a station on both sides of the tracks.
Firefighter safety. About one-fourth of the line-of-duty deaths occur while members are en route to or returning from calls. The driver operator needs to know how to get to the incident location. Traditional grid systems are easy to memorize. Some cities went so far as to alphabetize and numerically sequence streets in the grid. Memorizing streets and locations is simple in those cities. Contrast that with most emerging suburban street patternsthe officer is checking the map book and one less set of eyes is watching the road.
COMMUNITY GENERAL PLAN ELEMENTS
Given that the developers and traffic engineers are designing and building road systems that hamper emergency response, what can the fire service do to reduce the impact of these decisions? First, get involved in the initial planning stages of any roadway design. This starts long before a developer shows up at the community’s doorstep; this starts with preparing the Traffic Circulation element of the community’s General Plan (sometimes called the “comprehensive plan” or “master plan”). This is the first item the chief’s staff should consider. Other plan elements of interest to the fire department are the Land Use, Open Space, and Housing elements and the Capital Improvement Plan.
The General Plan for the community is in some ways similar to the constitution; it provides the basic legal framework for the development of the community, including its spatial arrangement and infrastructure. Getting in on the ground floor of the community’s development means getting involved with the writing of the general plan.
Safety. The community’s general plan usually has a number of elements that guide the future growth of the community. Safety is of primary importance. In the Fire Protection section of the plan’s Safety element, the fire department establishes standards that will apply to future growth in the community, such as response time maximums, fire station distribution, the ability to concentrate forces for fires of various types, and built-in fire protection requirements for facilities and buildings that outstrip the fire department’s capabilities.
Circulation.To enhance the fire department’s response capability, the plan’s Circulation element is of utmost importance. A four- and eight-minute response travel time criteria built into the Safety element does little good if the circulation element does not support that goal. Don’t be surprised that statements such as “Develop methodologies for preserving neighborhoods through the reduction of cut-through traffic” appear in the Circulation element; everyone wants to live in a quiet neighborhood with little traffic. Such statements can make their way unchallenged into the Circulation element based on the good intentions of keeping neighborhoods quiet and reducing through traffic.
However, they ignore the fact that the same limits on traffic circulation through neighborhoods also slow down emergency responses. Either crucial minutes will be lost, or the community will need more fire stations to compensate for fire station distribution. Until the fire department and other emergency responders participate in the discussions, this will continue.
Capital Improvement Plan. Many General Plans include a Capital Improvement Plan (CIP) that identifies specific public infrastructure needs required to fulfill the General Plan. It also identifies funding sources the community may use for each CIP element, such as a bond issue or development fees for fire stations. Often in General Plans, a Capital Improvement Plan is included as an appendix. This is often a good place to frame the discussion about the CIP costs inherent in a poor circulation system. Computer-generated response maps will illustrate the impact of various circulation design choices. Often people in community leadership are unaware of the long-term costs of decisions.
By participating in all aspects of the development of their communities’ General Plans, fire departments can ensure that their voices are heard during crucial decisions that will have enormous impact later as the community develops.
Specific plans.After developing the community General Plan, jurisdictions often develop specific plans for areas of the community anticipating growth. These specific plans fulfill the requirements of the General Plan and more specifically identify and locate particular infrastructure elements that the community deems essential such as schools, parks, major thoroughfares, libraries, and fire stations. Often at this juncture, planners can consider changes to the specific street alignments before construction and before there is a political battle to get the necessary changes.
Development plans.Most communities require the developers of major developments to submit preliminary maps and plans that identify the road system. Usually at this time, the developer also submits an Environmental Impact Report. Fire departments have an opportunity to review these draft plans and submit comments. If, and this is the big if, the General Plan includes the fire department’s needs in the Safety and Circulation elements, the fire department can impose these requirements during this review process. That does not mean that the various reviewing bodies will uphold the fire department’s requests, but it puts the fire department in a strong position to ensure that the developer meets its needs for emergency response.
If this whole treatise sounds like an argument for traditional square-block, straight-line street layouts in urban and emerging suburban areas, that is a correct assumption. When developers and traffic engineers argue that the topography is too steep or that curvilinear streets with little cul-de-sacs are beautiful, just remember San Francisco. Because San Francisco generally follows a traditional grid-pattern street layout across a steep and varying topography, it enjoys some of the finest views of any urban landscape in the world. The added bonus is that emergency responders benefit from rapid access to all parts of the city.
Endnotes
1. Federal Highway Administration, “Neo-Traditional Neighborhood Design,” Lesson 6, FHWA Course on Bicycle and Pedestrian Transportation, http://safety.fhwa.dot.gov/ped_bike/univcourse/swtoc.htm.
2. “Emergency Response and Traditional Neighborhood Street Design Fact Sheet,” Local Government Commission, 1414 K Street, Sacramento, California, May, 2007. Web site: http://www.lgc.org/freepub/land_use/factsheets/er_streetdesign.html.
3. “A New Perspective on Road Design,” Alternate Street Design, P.A. ,1516 Plainfield Avenue, Orange Park, Florida. Web site: www.roundabouts.net/roaddesign.html.
4. “Traffic Calming Measures,” Institute of Transportation Engineers, Washington, D.C., 2007. Web site: http://www.ite.org/traffic/tcdevices.htm.
WILLIAM R. SAGER is a 35-year-veteran of the fire service and a senior associate with Citygate Associates, LLC., which provides fire and emergency services consulting. He retired from the California Department of Forestry and Fire Protection in 2003; in his last assignment he served as the Butte unit chief and the Butte County fire chief.
