(Update 7/20/22- This page is being revised. Keep checking back to see new updates)
We all have experienced the difficulty of turning left onto US 9 and have witnessed the speeding through town along with vehicles crossing the double line to pass in the middle of town. Pocketville Road has a high volume of non-local traffic and speeders that use the road as a shortcut to Kolob. Other parts of town are starting to experience an increase in traffic violations on their streets. The Town plans to add commercial uses throughout town and across the river. When this occurs then other neighborhoods will start to feel the effects of increase traffic volumes, higher speeds, and depending on the location, cut-through traffic. It is time to start implementing traffic calming measures in established neighborhoods and change our subdivision rules to include traffic calming measures.
Traffic concerns in neighborhoods depends on the specific neighborhood but usually involve one or more of the following problems: speeding; cut-through traffic; conflicts between residential and commercial traffic; traffic jams at particular times of day, places, or event sites; intersection conflicts; and conflicts with other users of the roadway, such as pedestrians, bicycles, horses, golf carts, and electric scooters. Virgin neighborhoods have experienced mostly the first three issues: speeding; cut-through traffic; and conflicts between residential and commercial traffic with speeding being the primary problem.
We all have heard the phrase “speed kills”. Not only does speed kill when a driver hits another vehicle or leaves the road, but speed also kills pedestrians and bicyclists that are hit by a vehicle, even at normal speeds or driving slightly over the speed limit. See chart below. A trend across the nation is to reduce speed limits to 20 mph in residential areas. Also, employing traffic control measures along with enforcement and education is important in reducing speed.
Speed/Pedestrian Injury Severity Correlation – US Department of Transportation Federal Highway Administration citing C. E. “Rick” Chellman
Traffic calming is defined by the Institute of Transportation Engineers (ITE) as a “combination of mainly physical measures that reduce the negative effects of motor vehicle use, alter driver behavior, and improve conditions for non-motorized street users.” The physical traffic calming measures are often classified into four to six categories. The most common four categories: 1) vertical deflection; 2) horizontal deflection; 3) road width narrowing; and 4) barrier installation/diversions. Depending on the problem, (i.e., speeding, traffic volumes, or cut-through traffic), one or more of these calming measures may be employed:
Vertical Deflection
Vertical deflection is the modest raising of the street level or a portion of the street in some form or creating a texture change in the roadway. Textual changes in roadway cause reflexive slowing or at least more attention to the roadway. Examples of vertical deflection traffic calming measures are speed bumps, humps, tables and cushions; raised intersection; raised crosswalks; texture pavement; and rumble strips.
Speed bumps: are usually smaller than speed humps, tables and cushions. The bumps are generally 3 to 6 inches high and 1 to 3 feet long. They are typically used in residential areas.
Speed humps: are larger than speed bumps and are rounded mounds, approximately from 3 to 4 inches high and 10 to 14 feet long. Speed humps generally can slow vehicles down to approximately 15-20 miles per hour. The humps need to be placed at frequent intervals to deter acceleration between the humps. Photo of hump.
Speed tables: are a lengthened speed hump with a flat top. The design of speed tables allows for higher speeds than those of speed humps. They rise to meet the grade of the sidewalk and provide a safe crossing for walkers and wheelchairs. Photo of speed table.
Speed cushions: are a series of speed humps installed across the width of the street with spaces between them to allow passage for emergency vehicles, buses, large vehicles, and bicycles. Photo of speed cushion.
Raised intersection: are flat raised areas around the intersection with ramps attaching each approach to the intersection. The area is more noticeable when the level of the intersection and cross walks are raised.
Texture pavement: creates a surface that is unpleasant to drive over at high speeds due to the uneven texture of the surface. If driven over at higher speeds the texture will cause a noticeable vibration to the car.
Rumble strips: are grooved patterns placed in the pavement perpendicular to the direction of travel. When a vehicle passes over a rumble strip the driver feels a vibration and hears an audible rumbling sound and feels a vibration. This method is commonly used in high speed areas to give the driver advance warning to slow down or about an upcoming intersection.
Horizontal Deflection
Instead of deflection vertically like a speed hump, traffic is diverted horizontally. Instead of driving a straight path, a driver is forced to shift horizontally causing the driver to slow speed to navigate the traffic measure. Examples of horizontal deflection traffic calming measures are chicane; traffic circles and roundabouts, and intersection realignment.
Chicane: are a series of alternating curves or lane shifts that force a motorist to steer back and forth instead of traveling a straight path. They realign the road horizontally to force the driver to alter their path causing them to slow down.
Traffic circles and roundabouts: are raised circular islands placed in the center of the intersection. Roundabouts are larger traffic circles with splitter islands and yield signs at each entry way and are intended for larger intersections with higher traffic volumes. Traffic circles and roundabouts are very effective at slowing vehicle speeds down by forcing vehicles to make turning movements. Photo of roundabout.
Intersection realignment: is realignment of a straight approach of a standard T intersection into curving street so that the realigned street connects at a right angle. The new sweeping turn causes the driver to slow down to take the corner.
Street Width Narrowing
Narrowing the width of roadway forces drivers to slow down in order for the driver to safely and comfortably travel through the reduced passageway. Many communities now require more narrow streets in residential areas to slow traffic and discourage cut-through traffic, often referred to as skinny streets or road diet. Another advantage of smaller street is less pavement and therefore less stormwater runoff. Examples of narrowing width of street are chokers, neckdowns, angle points, center islands or pedestrian islands, and narrow streets with parking on both sides of street.
Neckdowns:
Angle points:
Center/pedestrian islands (medians): Medians are islands located along the roadway centerline. The islands separate opposing directions of traffic movement or narrows the width of street travel lanes. They can be either raised or flush with the level of the roadway surface. They can be painted pavement markings, raised concrete platforms, landscaped areas, or any of a variety of other design forms. Medians often accommodate pedestrians and bicyclists at crossings of major roads.
Narrow streets:
Barriers/Diversions
Half closures: are put in place to block a single lane of traffic. They prevent vehicles from entering a road but still allow vehicles to exit the road. The street remains a two-way street, but access at the closed end only allows for bicycle and pedestrian traffic. Partial closures are effective in limiting traffic on a roadway and turns off of the intersecting roadway. Half closures can be made by extending the curb or placing a barrier to block entry. Ample signage must be put into place to alert drivers to the partial closure. Half closures are used where a residential road is experiencing heavy amounts of cut-traffic due to its connection to a main road.
Full closures: are created by barriers usually at an existing intersection. The full closures can be a dead end or a cul-de-sac. An opening or trail can be placed to connect pedestrians and bicycles to the abutting road. The barriers can range from curb extensions to bollards to a fully landscaped closure. Road closures are very effective at lowering traffic volumes on the roadway. Cut through traffic can be greatly reduced.
Forced turn islands:
Gateway: is an entry treatment to the roadway or surrounding area that creates a sense of passage or change in traffic conditions to the area. Gateways may include posts, trees, bushes, signs, poles, or columns. They can also include curb extensions, changes in pavement color or type, or any other method that creates a sense of entry into an area. Gateways result in a small reduction of traffic and a slight speed reduction.
Other Traffic Calming Methods
Police enforcement:
Decrease speed Limits:
Variable speed dispay board:
Pavement markings: