Traffic Engineering
Road Diets

 

 

                                 

The City of Fresno, in partnership with the City of Clovis and County of Fresno, has implemented a number of “road diets” within their jurisdictions. A “road diet” is when a four lane, undivided roadway (2 lanes in each direction) is turned into a 3 lane roadway (one lane in each direction with a two way left turn lane in the center) and bike lanes are added. This new configuration not only enhances the safety for motorist but for cyclist and pedestrians, as well. A road diet creates a complete street for multiple modes of transportation.


It may appear that the road diet decreases the volume capacity of the roadway for motor vehicles since the number of through travel lanes has been decrease. In reality, a road diet improves traffic flow and increase safety by allowing vehicles making a left turn to pull out of the direct flow of traffic. The addition of the bike lanes also allows for motorist to decelerate out of the through lane and make a right turn as long as there is no cyclist next to or approaching them from behind. Please be sure to check your mirrors and over your shoulder before entering a bike lane to ensure a cyclist is not occupying the lane. The bike lanes also add travel ways for an alternative mode of transportation, offering residents a healthier, more economical and environmentally friendly choice of how to arrive at their destinations.

 
P Street Before Road Diet


P Street After Road Diet

 
Gettysburg Before Road Diet 

 
Gettysburg After Road Diet


 
Divisadero Before Road Diet


Divisadero After Road Diet



Divisadero Before Road Diet 

 
Divisadero After Road Diet


For more detailed information on road diets, please refer to the links below.

 Road Diets - Fixing the Big Roads by Dan Burden and Peter Lagerwey

Road Diets

Road Diets

Have you been down Fruit Avenue lately between Ashlan and McKinley or Divisadero between H and the CRMC Hospital? Maybe Dakota between Blackstone and Peach or Gettysburg between Blackstone and Fresno. The City of Fresno has been restriped these streets from 2 lanes in each direction without bike lanes to 1 lane in each direction with a center two-way left-turn lane (TWLTL) and bike lanes. We call this striping change a "road diet" (i.e. 4 lanes to 3 lanes). There are other variations that we have done to reduce lanes such as in downtown on M, P, Stanislaus, Tuolumne to help implement traffic calming measures such as diagonal parking or implement bike lanes.

One might ask, “were streets not working or why did the City change the striping?” It was working, however it was just not inclusive for all modes of transportation. A road diet more effectively and efficiently utilizes the right-of-way. With the air quality and health issues in the region the City of Fresno wants to enhance the infrastructure for all modes of transportation, so that people have the ability to ride their bikes on the same streets they drive their cars. As the Secretary of Transportation Ray LaHood states, “we cannot continue to build our roadways solely for the automobile. It is not a sustainable, economical, and healthy way to move people and people in America want choices available to them on how they can get to their destination.” The City of Fresno has completed the Bicycle Master Plan as required under Measure C half-cents sales tax that the voters of Fresno County approved. www.fresno.gov/BMP Changes and improvements are occurring within the City of Fresno to be a more Bicycle Friendly Community. In 2010, the City of Fresno lead the nation in bicycle facilities being installed with more than 30 miles of bike lanes, 3 miles of trails, and one million dollar grade separation trail crossing.

These new bike lanes on these streets connect and extent the existing bike lanes to help implement the Bicycle Master Plan and create a network system of bicycle facilities connecting bike riders with their desired destinations.

Extensive research has been done nationally and throughout the State of California (a few articles are available at www.fresno.gov/roaddiet) that show a road diet enhances the safety for motorists and cyclists, maintains the same volume capacity, and creates what transportation engineers/planners call a “complete street” for all modes of transportation. Road diets handle the same amount of traffic if not more and significantly reduce collisions.

The City does evaluate and study the roadways prior to the determining that this particular road will have a road diet and bike lane project. These road diet projects are consistent with the 2025 City of Fresno General Plan policies, goals, and objectives adopted by City Council in 2002 along with the City of Fresno Bicycle, Pedestrian, and Trails Master Plan and California Assembly Bill 1358 “Complete Streets Act signed into law by Governor Arnold Schwarzenegger in 2010.

The City is doing road-diets on a number of roadways throughout the City of Fresno, as funds are made available and it can be determined to be an acceptable solution with appropriate traffic engineering analysis. In older sections of Fresno that were not designed to accommodate bike lanes, road diets are one option to consider for installation of bike lanes. This reduces the need to remove residential frontage parking, purchasing front yards for parking bays, or widening the street and relocating the curb and gutter.

Myth #1 Road diets decrease the volume capacity that the roadway segment or intersections can handle.

This myth is not true. This might seem contrary to popular belief that two lanes can serve more traffic than one, but when motorists stop in the #1 lane to make a left-turn onto a local residential street, driveway or at an intersection they are in essence blocking the through traffic for that lane. When motorists slow down in the #2 lane to make a right-turn onto a local street or into their driveway they are also blocking this through lane.

Myth #2 Road diets decrease safety because there are less lanes.

This myth is also not true. When designing roadways transportation engineers/planners look at all modes of transportation. The four lane undivided roadway has motorists turning left and right out of the through lanes. Often this creates rear-end collisions because motorists are tailgating, driving too fast, or not paying attention to the vehicles in front of them. Through traffic then has to stop or go around this stopped left and right turn traffic. This stopped traffic could be for a pedestrian crossing the street that the motorists behind is not aware of because they think the car is stopped to make a left-turn. With a road diet left-turn movements can be made from the two-way left-turn lane (TWLTL). With the TWLTL motorists pull into the TWLTL or the left-turn pocket at the intersections to make a left-turn rather than stop all through traffic behind them. With the bike lane motorists can decelerate out of the through lane and make a right turn as long as there is not a cyclist next to them or approaching from behind. Please be considerate of cyclist as they cannot stop as fast as a motorists.

If visibility of oncoming traffic is difficult with 4 lanes of traffic then the visibility will be enhanced because the outside lanes will not be as close to the curb or parked vehicles. They will be separated by a bike lane.

The City of Fresno has three major street roadway classifications that we utilize to create our half mile grid system.

Expressway (Herndon Avenue)

Super Arterial and Arterial (Shaw Avenue)

Collector (Dakota Avenue)

Expressways typically are 6 lane roadways with limited access to the half mile signalized intersection and a raised median. The speeds are 45-50 MPH and they can handle 30,000-60,000 Average Daily Trips by vehicle daily. Expressways do not typically have on street bike lanes or sidewalks but rather a trail that runs parallel to the Expressway. Vehicle parking is prohibited.

Super Arterials and Arterials are 4-6 lane roadways with more median breaks at the 1/4 and 1/8 openings as well as at the signalized half mile intersections. They have raised medians and their speeds range from 35-45 MPH. They can handle between 20,000 – 45,000 Average Daily Trips by vehicle depending on the number of lanes. Super Arterials and Arterials are suppose to have sidewalks and on street bike lanes. Some also have a trail that runs parallel to the roadway. Vehicle parking can be allowed or restricted depending on the arterial, adjacent land use, and location.

Collectors are 2-5 lane roadways that do not have a median. Some of them are divided by a two-way left-turn lane. Access is not restricted on collectors so often residential homes and retail businesses and offices have many driveways. Their speeds range from 25 MPH to 45 MPH. They can handle between 5,000 – 35,000 Average Daily Trips by vehicle depending on the on street parking, number of driveways, presence of a two-way left-turn lane, and number of lanes. Collector roadways are suppose to have sidewalks and on street bike lanes. Vehicle parking can be allowed or restricted depending on the collector, adjacent land use, and location.

Evaluation of Collectors

The City of Fresno regularly monitors the 85th percentile speed, traffic volume, and accident information of half mile roadway segments through the City. In some cases based on this information the City of Fresno Public Works Department, Traffic and Engineering Services Division has made the determination that the lane configuration should or could be modified. We are only making these modification on collector streets. For instance, on a collector that is four travel lanes and has an Average Daily Traffic Volume of 18,000-20,000 or less a three lane roadway (one lane in each direction with a two way left-turn lane and bike lanes) could be implemented and be able to serve the same amount of traffic volume. The speeds might be a less but the vehicles are still moving through the corridor. The vehicles may also be controlled by the prudent drivers speed rather than the ability to be the first vehicle racing down the corridor.

Collectors and Arterials typically flip every other half mile on our grid system. Collectors are not intended to be high speed roadways for long distance travels across the City. Collector streets are intended for short trips and to connect a motorist with an adjacent arterial or freeway. That is why they are called “collectors” as they help collect traffic to bigger, faster, and more access controlled streets that can move vehicles more efficiently and effectively.

As a result, collector streets can often make great roadways for bike riders as the speeds and volumes on collectors are typically much lower than arterials. This is why many of these collector streets have been chosen by the City of Fresno, City of Clovis, and County of Fresno within the Fresno/Clovis metro area for road diets to provide not only a network of travel lanes for motorists but also bike riders. This transformation via a road diet is consistent with Assembly Bill 1358 “Complete Streets Act”

Accidents and Public Safety

There are three main types of vehicle-vehicle accidents that occur on undivided four lane roadways that can be substantially reduced by installing a road diet to a three lane roadway (one lane in each direction, two way left-turn lane, and bike lanes). These accidents are usually caused by inattentive or distracted drivers, drivers that are driving too fast for the conditions of the roadway (which maybe apparent to the driver or not), stopped vehicles that motorists are not anticipating, sight distance visibility of two motorists trying to make conflicting left-turns, motorists weaving in and out of lanes to pass each other in between traffic signals, and avoidance of a stopped vehicle.

Below are the figures demonstrating the three main types of accidents.


Rear Enders

A red vehicle motorist stops in the #1 through lane to make a left-turn. This red vehicle motorists is now blocking the through lane. The blue vehicle behind the left-turn red vehicle does not realize the red vehicle is stopped, is driving too fast, or tailgating. The blue vehicle rear-ends the red vehicle. With the road diet, the red vehicle pulls into the two-way left-turn lane to make a left-turn thereby keeping the through vehicle lane open for the yellow and blue vehicle motorists to continue unimpeded. Removing the left-turn vehicle motorists from the through lane motorists is where the greatest unaccepted speed differential occurs.


Side swipes

A red vehicle motorist stops in the #1 through lane to make a left-turn. This red vehicle motorists is now blocking the through lane. The blue vehicle behind the left-turn red vehicle does not realize the red vehicle is stopped, is driving too fast, or tailgating. The blue vehicle then swerves into the number two through lane and side swipes the yellow vehicle. With the road diet, the red vehicle pulls into the two-way left-turn lane to make a left-turn thereby keeping the through vehicle lane open for the yellow and blue vehicle motorists to continue unimpeded. Removing the left-turn vehicle motorists from the through lane motorists is where the greatest unaccepted speed differential occurs.


Broadsides

A red vehicle motorists stops in the #1 through lane to make a left-turn in both directions. This red vehicle motorists is now blocking the through lane and the sight visibility of the opposing red vehicle motorists. As a result of the reduced sight visibility the red motorists turns in front of other red motorists but broadsides the yellow vehicle as the red vehicle could not see if the yellow vehicle was approaching in the open through lane. With the road diet, the red vehicles pull into the two-way left-turn lane to make a left-turn thereby keeping the through vehicle lane open for the yellow as well as allowing each other to see oncoming vehicles.

Design and Maintenance of our Roadways and Freeways

Our current level of service thresholds have both the State of California and the City of Fresno designing our infrastructure for the worst 15 minute period of the day. Level of service is a comparison between true capacity of a roadway and the demand for the roadway. As a result, many of our streets are substantially overbuilt for 22-23 hours of the day. An economist would say that this is not a great return on our investment in infrastructure. A motorists would say that this is a great return on our investment in infrastructure. More than 95% of all roadways are installed by new development so ultimately it is the home buyer or the shopper that is paying for the roadway. The remaining 5% of all roadways are installed by grants, Measure C half-cent sales tax revenues, and federal and state taxes.

When roadways are overbuilt for 22-23 hours of the day, it also costs more for jurisdictions to maintain the additional asphalt that is only needed for 15-60 minutes of the day. The roadways also contribute to the urban heat index during the summer which affects our air quality.

Fresno was ranked by Forbes Magazine in 2010 as one of the Best Large Cities to commute in the Nation. We are one of the only, if not the only City of a half million people in which you can travel by vehicle from the north side of town to the south side in approximately 15-20 minutes depending on the time of day. On top of that we are one of the largest Cities (land mass wise) as our development is not as dense as most other large Cities. We also lead the State of California in number of freeway lane miles per capita, as well as, local jurisdiction major street lane miles per capita. We have a lot of reserve capacity in our roadways.



The City of Fresno is leading the Central Valley in the Implementation of the Intelligent Transportation System. Synchronizing our corridors allows for more efficient, effective, and safe movement of our motorists. We are starting with our highest traveled corridors based on volume and congestion as that is where we get the most return on investment for improved air quality, fuel consumption, and travel time reductions. More information can be obtained at www.fresno.gov/ITS.


The picture below is automobile congestion. However, the City of Fresno does not have a street in Fresno that is under grid lock like this for more than a few minutes other than around a shopping center during the holidays or a major event. Often what people in Fresno refer to as congestion is that they are not able to drive as fast as they want to which for many public safety reason is not beneficial to a community.
 

However, we can look at that congestion in a different way. We can ask our self, how many people are we actually moving on that street and is there a better way to move people than in a single occupant vehicle all at the same time, 10-15 minutes before they need to get to their destination.


When motorists driving 30-50 MPH in Fresno say they never see a pedestrian or bike rider in Fresno, they may be telling the truth due to the tunnel vision of a motorist focusing only on what is in front of them rather than what is around them. Ever wonder why retail businesses try to have the biggest and brightest sign possible? They are trying to attract your tunnel vision on their sign. This is why it is so important as a motorists to pan from side to side in front of you and regularly to check your mirrors to know what is around you. It is also the reason why to focus on driving rather than anything else while driving a vehicle.




Bulbouts like the ones shown below and what have been installed in Chinatown and near Kern Street downtown along with the Olive/Wishon intersection in the Tower District reduce the crossing width for a pedestrian and also enhance the visibility of a pedestrian for oncoming motorists.






This bike rack area at Figarden Elementary normally has approximately 15-20 bikes at it on any given day. However, in 2009 the City of Fresno along with the Fresno County Bicycle Coalition, Figarden Elementary, and Fresno Unified School District had a “Bike to School Challenge”. Nearly 250 of the 600 students road their bike to school on that day. So many students road their bike that school ran out of bike racks. Surprisingly the vehicle congestion around the school on that day was a lot less than normal. This event not only showed that we can improving public health and physical fitness but also reduce the emissions and congestions for vehicles around the school. In the last generation we have experienced a decrease in biking and walking to school from 50% to now approximately 10%-15% of the students. In the same generation, childhood obesity in our region has more than tripled. Why can’t every day by a Bike or Walk to School Day like it used to be?









2010 Bicycle, Pedestrian, and Trails Master Plan

transforming the City of Fresno into a more bicycle friendly community…

Go to www.fresno.gov/BMP to review!

In addition this BMP, when adopted, will greatly enhance the City of Fresno’s ability to successfully apply for and become a medal award recipient as a Bicycle Friendly Community, as determined by the League of American Bicyclists. This award is an incredible prestige and honor to receive as it denotes that the City of Fresno is a bikable community, which is one instrumental characteristic and attribute of a sustainable, livable, and quality City. The City of Fresno would be the first City in the valley from the Tehachapi Mountain Range to Sacramento and from the Sierra Mountain Range to the Coastal Mountain Range to receive such an honor. There are currently over 30 cities in California that are a medal award recipient (Platinum, Gold, Silver, and Bronze) as a Bicycle Friendly Community including such cities as Davis, Palo Alto, San Francisco, Folsom, San Luis Obispo, Santa Cruz, Chico, Huntington Beach, Irvine, Long Beach, Oakland, Oceanside, Riverside, Roseville, Sacramento, San Jose, Santa Clara, Santa Monica, Sonoma, South Lake Tahoe, Sunnyvale, and Thousand Oaks. The City of Fresno, with this Bicycle Master Plan, is emerging as a leader and role model in the central valley on how to transform a city into a Bicycle Friendly Community and show that this prestige is achievable in the valley.