1. ROAD DIETS Module 10 After Before 1 of 9 Safety Proven Countermeasures
This term may be new to many in the audience. This last session brings us back to the opening session, where the point was made repeatedly that overly wide roads are hazardous for pedestrians to cross. This session explores ways roads can be narrowed, without capacity suffering unduly.
1 of 9 Safety Proven Countermeasures 1

2. Learning Objectives
At the end of this module, you will be able to:
Describe how ped crash risk increases with number of travel lanes and speed.
Explain why reducing # of travel lanes reduces risk, and makes it easier to cross the street
Demonstrate how reducing lanes frees space for higher & better use:
Streets exist 24/7; peak traffic may be a concern for as little as 30 minutes a day
The last point is important: there is a chance a road diet will increase congestion (decrease LOS) at peak periods, but the road may operate a lot better the rest of the day.

3. “Classic Road Diet” 4 to 3 lanes San Antonio TX
In most people’s minds, this is what is understood by the term road diet. We’ll discuss it, but show some other options.
4 to 3 lanes

4. Road diets: reclaim street space for other uses
Bike Lanes
Median
On-street parking
A road diet typically reduces the number of travel lanes on a road, and dedicates the space to other uses. Road diets usually result in enough room to provide bike lanes, but that’s not the only benefit.
Center Turn-Lane
Seattle WA
Road diets: reclaim street space for other uses

5. https://safety.fhwa.dot.gov/road_diets/guidance/info_g uide/rdig.pdf
Resource for Road Diets
FHWA Road Diet Informational Guide
Summary of design guidance and considerations for conversions
Case studies and project examples
uide/rdig.pdf

6. Road Diets and Traffic Safety
First we explore how a road diet affects traffic operations.

7. 3 crash types can be reduced by going from 4 to 3 lanes: which ones?7

8. 3 crash types can be reduced by going from 4 to 3 lanes: 1 – rear endersX 8

9. 3 crash types can be reduced by going from 4 to 3 lanes: 2 – side swipesX 9

10. 3 crash types can be reduced by going from 4 to 3 lanes: 3 – left turn/broadsideX
This is a “multiple threat” for drivers. 10

11. Case Study: San Francisco, CA
Why a Road Diet?
Community recognized need to accommodate other road users
Large number of pedestrian attractors led to conflicts
Bicycle community wanted dedicated bicycle lanes
Background: The city recognized they needed to accommodate other road users, and the bicycle community wanted a road diet to occur, but the local department of transportation was initially unwilling to reduce capacity along this important north-south corridor that can be used as a surface street alternative to the Central Freeway.
Yet due to the increasing number of restaurants, shops, and bars, and the increasing number of conflicts with pedestrians and bicyclists, the Board of Supervisors voted on a resolution in November 1998 calling for the removal of two travel lanes and the installation of bicycle lanes and a median lane for left turns on a one-year trial basis.

12. Case Study: San Francisco, CA
Problem/Background
Valencia Street part of San Francisco’s Mission District
1.8 miles long
4-lane road with 22,000 ADT
High pedestrian, bicycle, bus activity but lacked supporting infrastructure
Before
Problem/Background: The first case study looks at a road diet performed on San Francisco's Valencia Street. The street is part of San Francisco’s Mission District, a historically low-income, working-class neighborhood, but an area that the city focused on for revitalization in the 1990’s and 2000’s. Prior to the road diet, the 1.8 mile arterial was a four-lane street, with parking lanes, and an Average Daily Traffic (ADT) of approximately 22,000 vehicles per day. There was also a heavy pedestrian presence, and high bicycle and bus activity, even without supporting infrastructure.

13. Case Study: San Francisco, CA
Details
In 1999, 4 lanes restriped to 2 lanes + bicycle lanes and center turn-lane
Trial basis
Speed limit lowered from 30 to 25 mph
Signal timing altered to minimize loss of capacity
Made permanent after year trial
Initial cost: $130,000
Paint and sign work, & labor spent writing an impact report
Before
After
Details: In 1999, the four road lanes were restriped to two, with bicycle lanes and a median turn-lane added. The speed limit was lowered from 30mph to 25mph. To minimize the loss of capacity along Valencia Street and reduce the impacts to parallel streets, the signal timing was altered to promote a smoother progression at the new 25mph speed limit.
After the year trial period ended, the city decided to make the changes permanent, since the fears of lower capacity and increased traffic on adjacent streets never materialized.

14. Case Study: San Francisco, CA
Results
Success
No real change in ADT
Large increase in cycling & pedestrian activity
Reduction in collisions
Aided revitalization of area
Four years after, a survey of business owners along Valencia Street found general support*
65% felt bicycle lanes had positive impact on their business, only 4% said it had negative impact
65% would support more traffic calming
Results: The Valencia Street road diet was widely considered a success. ADT on Valencia street declined 10 percent, but the increase was not diverted to a single parallel street but rather adjacent roads each saw a slight increase. Total collisions declined, and while bicycle collisions rose approximately 50 percent, the increase was outpaced by the 140 percent increase in ridership on the street.
Public responses were also received during the year trial. A hotline advertised on the route received 286 recorded calls, of which 259 were supportive of the project and 27 were opposed. Of letters and s received, 39 supported the project while three did not. A postcard campaign led by the local bike coalition yielded 484 supportive post cards and four not supportive.
The restriping also helped aide revitalization of the area, with many shopkeepers noting increased sales after the change to the streetscape. A study completed four years after the initial road diet found 65 percent of businesses felt the addition of bicycle lanes positively impacted their businesses, while only 4 percent said it had a negative impact. Additionally 65 percent supported more traffic calming along the street.
*Source: Emily Drennen, “Economic Effects of Traffic Calming on Urban Small Business”

15. Case Study: San Francisco, CA
Results
City implemented more changes in 2010:
sidewalks and bike- lanes widened
bulb outs, streets trees, lighting, and public art added
Became place to try new treatments such as bicycle “green wave” and bicycle bays
Sign indicating the street is set for “green wave” speeds
Results: The initial changes were ultimately so successful that additional changes were implemented, such as: Widened sidewalks, Bulb outs, Widened bike lanes, adding street trees, decorative lighting and public art, On-street bike parking, and truck loading zones. The street has also become a place to try new technologies, such as bi-directional 13mph “Green Wave” for safer steadier traffic speeds for all road users.
The street has also become one of the city’s highest-use bicycle corridors. A 2011 count recorded 700 cyclists during a 1.5 hour count.
The road diet has been seen as a success story of the benefits road changes can have for all users.
Sign illustrating a bicycle bay

16. Which road carries more traffic?
San Antonio TX
Which road carries more traffic?
Which road produces the higher speed?
With a 4-lane road a fast driver can pass others
With a 2-lane road the slower driver sets the speed
Which road produces the higher crash rate?
Which is better for bicyclists, pedestrians, businesses?
Animated – click one question at a time; let participants answer before moving onto next question. Answers:
More traffic – it depends. Both are about equal up to 15,000 ADT or so; 3-lane performs better if there are a lot of left turns.
Speeds: a 4-lane allows a driver to pass others at high speeds; 3-lane prevents fast drivers from passing others slow driers set the speed)
Crashes: 3-lanes has fewer crashes – all types.
3-lane is better for other users too. 16

17. Road Diet CMF = 0.47 & 0.71 (CRF = 53% & 29%)
Orlando FL
TRR 1593 “Iowa’s Experience with Road Diet Measures”, Michael Pawlovich, Wen Li, Alicia Carriquiry, and Tom Welch. A Bayesian Before-and-after data analysis by Iowa State University for 30 sites with 15 study sites with 15
Source CMF Clearinghouse 17

18. What are some benefits of road diets for pedestrians?
Reduce crossing distance
Eliminate or reduce “multiple threat” crash types
Install crossing island to cross in 2 simple steps
Reduce top end travel speeds
Buffer sidewalk from travel lanes (parking or bike lane)
Reclaim street space for “higher and better use” than moving peak hour traffic
Animated – let participants give some answers before clicking. They probably won’t get all of them, that’s okay. 18

19. Before
Charlotte NC
Reclaiming road space creates room for ped islands

20. After Before Reclaiming road space creates room for ped islands
Charlotte NC
Reclaiming road space creates room for ped islands

21. This 5-lane Main Street was converted to…
There are many possibilities; a typical 5-lane can be converted too (next slide).
Pottstown PA
This 5-lane Main Street was converted to… 21

22. Name 4 things that changed
Animated: wait for participants to answer before clicking. In most cases the 4th change is not noticed (the new pavement).
Note on one side parallel parking was changed to back-in diagonal parking, much better for cyclists and drivers. They took advantage of a repaving job to make all three changes at once. Discuss advantages of back-in diagonal parking (drivers can see traffic when exiting, better for cyclists)
Pottstown PA
Fewer travel lanes; added bike lanes; parallel to back-in diagonal parking on one side; new pavement 22

23. There’s potential on one-way streets too:
One-way streets have high potential, as they tend to be overbuilt. In this example, most of the street is underutilized. This photo was taken off-peak, but it is the way the street looks most of the day.
Boise ID
There’s potential on one-way streets too:
Is this street operating at capacity? 23

24. It‘s important to note that removing 1 of 3 travel lanes does not reduce the capacity by 1/3, since each additional lane does not add as much capacity as previously-added lanes. This is due to reduced signal efficiency, friction, and other factors. Also note that in this case bike comfort and capacity is increased through the addition of 2 bike lanes, which also provide additional buffer to pedestrians.
Sacramento CA
Example of one way street converted from 3 lanes to 2 lanes (plus 2 bike lanes) 24

25. One-way streets have high potential, as they tend to be overbuilt
One-way streets have high potential, as they tend to be overbuilt. Many 4-lane two-way streets were converted to 4-lane one-way streets with no analysis. In many cases, 3 lanes in one direction carries traffic just as well. In this example, the street life came about after the roadway was narrowed form 4 to 3 lanes, crating space for bike lanes and wider sidewalks.
Portland OR
This area was recaptured from a 4th travel lane; the street took on a whole new life 25

26. Road Diet Learning Outcomes
Describe how ped crash risk increases with number of travel lanes and speed.
Explain why reducing # of travel lanes reduces risk, and makes it easier to cross the street
Demonstrate how reducing lanes frees space for higher & better use:
Streets exist 24/7; peak traffic may be a concern for as little as 30 minutes a day
You should now be able to:
The last point is important: there is a chance a road diet will increase congestion (decrease LOS) at peak periods, but the road may operate a lot better the rest of the day.

27. Questions?