El Paso is one of the fastest growing counties in Colorado.  With all the benefits that growth provides, it also means more traffic.  And with increasing traffic can come congestion.  Once congestion reaches the point where rush-hour speed drops to half of mid-day speed, commuters begin looking for bypass routes.  Unfortunately, the bypass route is frequently one of the neighborhood streets where most of us live.

Nationally, neighborhood streets have some of the highest pedestrian and cyclist injury rates of all road types. Excessive cut-thru traffic is a key factor jeopardizing the safety of our neighborhood streets.  Fortunately, there are a number of traffic calming measures for making neighborhood streets safer by reducing and slowing cut-thru traffic.  Examples include raised pedestrian crossings, speed tables, chicanes or roundabouts. It appears though that unlike other Colorado localities, El Paso County (outside Colrado Springs) has yet to embrace traffic calming.  Fortunately, the County is in the process of adopting a Local Road Safety Plan, which would be an excellent opportunity to also make far greater use of traffic calming measures.

Furrow Road – One of 67 El Paso County Road Projects

Furrow Road, in the Monument area south of Route 105, is an excellent example of how growth may cause a dramatic increase in traffic.  The aerial to the left shows Furrow Road as it exists today and the red dashed line is the proposed extension of Furrow Road to Higby Road.

The present traffic volume on Furrow Road is 900 vehicles/day.  With the proposed extension Furrow Road traffic volume could reach 5,000 vehicles/day in a decade or two!

Those living on Furrow Road and connecting neighborhood streets treasure it as a place to safely walk or bike with their children.  This will no longer be possible once Furrow Road is opened to thru traffic.  However, traffic calming measures would reduce vehicle speed and could cut traffic volume by a third to half.

While traffic calming will not keep Furrow Road as safe as it is today, these measures would prevent it from becoming a commuter raceway.  It is for these reasons that we ask you to sign our petition calling upon the El Paso Board of County Commissioners to swiftly move forward with policies that:

• Only open neighborhood streets to thru traffic when absolutely necessary, and
• Adopt traffic calming programs like those of Colorado Springs, Larimer County, and Boulder to name but a few.

Road Projects May Affect Neighborhood Streets Countywide

The map below shows 67 road projects proposed in the El Paso County 2016 Major Transportation Corridors Plan.  While we do not doubt that these are all worthwhile projects, we are concerned that some – like the Furrow Road extension, which is project N16 – will subject some neighborhood streets to thru traffic and increase the volume of traffic on streets already open to cut-thru traffic.  It is imperative that El Paso County evaluate the effect each of these projects may have on neighborhood street safety and ensure that calming or other safety measures are installed before each road project is completed.  So please sign our petition urging the El Paso County Commissioners to take both actions.

Quiet Neighborhood Street vs. High Cut-Thru Street Benefits

Those who live on quiet streets paid a premium of 20% or more to enjoy the enhanced quality of life motivating their choice.

Opening these streets to large volumes of through traffic interferes with the close neighbor relations that adds so much to quality of life. For example, one sociologist found that:

“people who live in traditional bulb cul-de-sacs (dead-end) have the highest levels of attitudinal and behavioral cohesion (covering both how they feel about their neighbors and how much they actually interact with them). People who live on your average residential through-street have the lowest levels…”

For parents living on courts or other low-volume streets, a rise in traffic volume may increase anxiety about allowing children – particularly younger kids – to play outside. Children between the ages of 5 and 9 are particularly at risk to traffic-caused injury. Opening these streets to large amounts of through traffic robs both children and their parents of a sense of safety and freedom many cherish.

With regard to crime, one study noted that:

“Furthermore, hierarchical, discontinuous street systems have lower burglary rates than easily traveled street layouts; criminals will avoid street patterns where they might get trapped. For example, the troubled Five Oaks district of Dayton, Ohio, was restructured to create several small neighborhoods by converting many local streets to cul-de-sacs by means of barriers. Within a short time traffic declined 67 percent and traffic accidents fell 40 percent. Overall crime decreased 26 percent, and violent crime fell by half. At the same time, home sales and values increased.”

Why does cut-thru traffic make neighborhood streets more dangerous?

Cut-thru traffic tends to operate at a higher speed, which increases the likelihood of accidents and the severity of injury for the reasons shown the following graphic:

• a pedestrian is nearly twice as likely to die if struck by a car traveling at 30 mph compared to 20 mph,
• as speed increases a driver’s field of vision narrows, which makes it more likely that pedestrians and cyclists will not be seen until its too late to avoid an accident, and
• a car travelling at 30 mph requires twice the distance to fully stop compared to 20 mph.

Making Neighborhood Streets Safer Success Examples

Here are a few success examples showing that it really is possible to greatly increase safety:

• Speed humps and other traffic calming measures have reduced crashes on neighborhood streets by up to 45%, 
• Holding back left-turning traffic for 3-7 seconds at signalized intersections has reduced pedestrian injuries by 60%, and
• A sizable portion of cut-thru traffic can be attributed to apps that steer drivers from congested main roads onto neighborhood streets. Very frustrated officials in one town felt they had no choice but to close off neighborhood streets to rush hour cut-thru traffic.

These are but a few of many examples of successful neighborhood street safety campaigns. This goal is best achieved by mobilizing the widespread support needed to allow government to conduct a comprehensive analysis of opportunities such as those serving as the basis for Vision Zero plans. El Paso County recently launched a similar effort known as Toward Zero Deaths.  The measures to achieve the Vision Zero and Toward Zero Death goals are addressed in further detail below.

How Much Traffic Is Too Much for a Neighborhood Street?

While every through-street will carry traffic from one main road to another, neighborhood quality of life suffers when the volume crosses a certain threshold.

Where is that threshold?

The table below is from a paper that appeared in the Institute for Transportation Engineers Journal. The term “environment” in the table is defined as:

“one where residents can live, work and move about in freedom from the hazards of motor traffic.”

To put these numbers in perspective, each single-family home generates one peak-hour trip and ten trips per day. These trips include the cars and SUVs driven by residents along with delivery trucks and all other traffic entering-exiting a neighborhood. One would anticipate that those who live on a residential street prefer that traffic volume remain in the good to excellent range or less than 600 vehicles per day.

With regard to Furrow Road, the extension to Higby Road would occur as part of the Grandwood Ranch housing project.  The Grandwood Ranch traffic impact study noted that the current traffic volume on Furrow Road is 900 vehicles/day, which is within the Acceptable range given in the table above.  Once Furrow Road is opened to Higby Road, traffic volume is projected to initially increase to 1800 vehicles/day, placing it in the Poor range.  The applicant’s study also shows that by 2040 the Furrow Road connection will result in nearly 5000 vehicles/day – more than a five-fold increase compared to today!  

At What Point Does Main Road Congestion Cause Excessive Cut Thru Traffic?

Commuters begin seeking alternate routes when congestion cuts main road (arterial-collector) speed to half the free-flow (late-morning) speed. For example, if free-flow speed is 40 mph then drivers begin seeking out alternates when congestion causes average speed to drop to 20 mph. Sadly, the alternate route is frequently a through-street bisecting a residential neighborhood.

As shown in the figure below, traffic congestion is rated using a system known as Level of Service or LOS.  The rating goes from A to F.  The “half-free-flow-speed” where drivers begin seeking alternate routes in earnest lies between a Level of Service of C to D. So, to keep cut-thru traffic at a reasonable volume main road traffic congestion should not reach Level of Service D-E or F.

Traffic Calming Measures

The goal of these measures is first to slow traffic speed then reduce excessive traffic volume. Both actions make neighborhood streets safer for those crossing or walking-biking along the street and less hazardous for children playing nearby.  The following table summarizes the effectiveness of three categories of approaches for making neighborhood streets safer.

Traffic calming is divided into three areas: education, enforcement and engineered measures. While all three are vital, only engineered measures provide lasting benefits. The following discussion is based mostly on the Center for Problem-Solving Policing webpage Responses to the Problem of Speeding in Residential Areas. Other traffic calming resources can be found at:

• Institute for Transportation Engineers, and
• Project for Public Space.

Education

These measures can range from a brochure to half-day programs given at local schools. Education must be the first step in any traffic calming effort. Before installing speed humps or other engineered measures on a neighborhood street it is essential that residents learn why they are needed. Residents must then have an opportunity to participate in decision-making about what approaches will be used. If done right most residents will support the effort.

Enforcement

Police departments have found that enforcement can be effective if four criteria are met:

• drivers believe they’ll be ticketed if they speed,
• it has meaningful costs to offenders,
• police apply it generally, rather than at specific times and locations, and
• drivers are not tipped off by cues as to when enforcement is or is not happening.

Speed cameras can be effective.  Other measures, like the speed sign to the right, only reduce speed for a few weeks. Every neighborhood seems to have a couple of residents who insist upon driving ridiculously fast. Most police departments will visit these individuals at home if alerted by other residents. This can be effective. Arresting the most severe offenders is quite effective but may require legislation giving police the authority to take this action.

Engineered Measures

These traffic calming measures range from safer crosswalks to closing off a street to through traffic.

Speed Humps span both travel lanes and are typically two- or three-inches high. They reduce speed to 20 or 30 mph. They are easier to cross and more acceptable to emergency services than speed bumps.  However, they may not be appropriate for main roads used by emergency services.

Traffic Circles reduce mid-block speed by 10% and intersection collisions by up to 70%. Roundabouts or rotaries are similar but are used where larger traffic volumes are anticipated and typically have two lanes of traffic in the circle. traffic circle

Chicanes are installed mid-block to narrow a street or to impart gentle curves, both of which cause drivers to slow-down. By narrowing the width of the street, chicanes also make it safer for pedestrians to cross.

Center Island Narrowing provides a safer crossing for pedestrians and can reduce speed. Some emergency service agencies find this to be the most acceptable calming measure. center island

If cut-through traffic becomes excessive on a narrow, neighborhood street then one option is to close the street off at one end. Simply making a street one-way can reduce cut-through traffic by half.

Measures With Limited Effectiveness

The following measures have been found to have minimal impact upon speeding:

• Reducing speed limits,
• Increasing fines and penalties,
• Stop signs, and
• Speed bumps (as opposed to humps) and rumble strips.

How to Ensure Measures Really Do Calm Cut-Thru Traffic

Many transportation agencies face a conflict when it comes to traffic calming measures. On the one hand, no one would argue that calming measures make neighborhood streets safer by discouraging cut-thru traffic. On the other hand, traffic agencies rely upon cut-thru traffic to reduce main road congestion.

This conflict can result in the design of calming measures that serve more as a pacifier rather than achieving the goal of safer neighborhood streets. For example, one study showed a substantial difference in the effectiveness of speed humps with an entrance ramp slope of less than 5%. This same study documented that speed humps spaced 82 feet apart achieved a 25% lower speed compared to a spacing of 1300 feet. Combined, a slope of >5% and spacing of 82 feet slowed traffic by an average of 5 mph more compared to speed humps with <5% slope and 1300-foot spacing.

It is not uncommon that folks say that while their neighborhood streets have speed humps or other calming measures they do not seem to have much effect on cut-thru traffic volume or speed. We suspect the poor performance is mostly due to poor design. In other words, the measures may have been designed more as pacifiers than to achieve a significant improvement in neighborhood street safety.

The recommended spacing for speed humps is every 260- to 500-feet. A typical speed hump:

• Extends from edge of street pavement to edge of pavement,
• Has a length of 12 feet, which
• Means it must be at least 3.6-inches high to achieve a 5% entrance ramp slope.

If the speed humps on your street do not meet these specifications then they may be less than fully effective. Contact CEDS at 410-654-3021 or Help@ceds.org to discuss speed hump design.

Liability & Traffic Calming

Concerns about liability are occassionally voiced by cities, counties, or other jurisdictions considering the use of speed humps and other traffic calming measures.  The following text from a U.S. Federal Highway Administration guidance document shows the liability concern is exagerated when it comes to traffic calming:

“2.7 Legal Issues Liability

Few jurisdictions have been successfully sued over liability issues related to traffic calming measures. The successful lawsuits have generally been the result of improper or inadequate maintenance of signs or pavement markings, not because a traffic calming measure was determined to be inherently unsafe.

It is the duty of the public entity to make sure the roadway system is safe for the intended use of that roadway. In order to establish negligence on the part of a public entity, the injured party must establish (1) that the government agency owed a duty to that person, (2) that the duty was breached by an act or a failure to act, (3) that the breach of duty was the proximate cause of the injury or loss to the complainant, and (4) that the government had adequate notice of the dangerous condition.

In order to minimize the potential for any liability, a public agency should develop and maintain documentation of every step in the traffic calming program process.

Emergency Vehicles & Traffic Calming

Some traffic calming measures slow both passenger vehicles as well as fire, ambulance, police, and other emergency traffic.  There’s a strong correlation between how long it takes emergency service vehicle to reach a scene and the loss of life or property.  Measures which significantly slow emergency vehicles should be avoided on main travel routes while neighborhood streets can fully benefit from calming measures.  The Federal Highway Administration guidance document Effects of Traffic Calming Measures on Non-Personal Passenger Vehicles provides detailed guidance regarding Traffic Calming Measures Developed to Address Emergency Service Vehicle Delay Issues.  Another very informative document is Emergency Response: Traffic Calming and Traditional Neighborhood Streets.  Another very informative publication is Emergency Response: Traffic Calming and Traditional Neighborhood Streets.

An emergency-services-only access structure is one option for improving response time without endangering a neighborhood with increased cut-through traffic.  Below are illustrations of common access structures, which can only be opened by fire, ambulance, police or other emergency services personel.