S. Dixie Highway Road Diet

On Saturday March 28 the Treasure Coast Planning Council held a public design workshop for the section of South Dixie Highway from Albemarle Road north to Okeechobee Blvd. On everyone’s mind was a road diet for this section of South Dixie Highway. The default road diet in these situations is to convert the existing four lane section to a three lane section with parallel parking on both sides. This is a tried and true method and it would be a fantastic improvement.

However, there is an alternate design that should be considered. The inspiration for the alternate design was a postcard of Clematis Street in the early 1900s with a single row of angled parking in the middle of the street

Clematis Avenue, Looking West from the Palms Hotel State Archives of Florida, Florida Memory, http://floridamemory.com/items/show/152572
Clematis Avenue, Looking West from the Palms Hotel
State Archives of Florida, Florida Memory, http://floridamemory.com/items/show/152572

and a recent award winning complete complete street project in Lancaster California with angled parking in the center of the street. The street, shown below, is referred to simply as the Boulevard.

Lancaster Boulevard - After
Lancaster Boulevard – After

The Lancaster Boulevard transformation resulted in hundreds of millions of dollars of private investment along the corridor. (A google street view link of the Boulevard is at the end of the post)

This is what Lancaster Boulevard looked like before the road diet:

Lancaster Boulevard - Before
Lancaster Boulevard – Before

For reference, below is a photo of S. Dixie Highway in the study section. Note the four travel lanes and parallel parking on the east side of the road. In some areas the parallel parking area is replaced by a landcape buffer.

South Dixie Highway - Existing
S. Dixie Highway (Existing) in study area

and here is what S. Dixie could look like in the study section using a mashup of the alternating direction angled parking from the historic Clematis photo and the ramblas of Lancaster Boulevard:

Proposed Dixie Highway center parking

Here is a street mix section (note: existing dimension were estimated from google earth):


Note – It gets even better south of the study area. There is wider right of way that would allow for two lanes with a single row of angled parking in the middle and parallel parking along the sidewalk side like this:

Dixie Hwy. with center angled and outside parallel parking
Dixie Hwy. with center angled and outside parallel parking

In order to have a successful street where people will walk it needs to be comfortable. Two important elements of a comfortable walk are shade and cars that travel less than 30 miles per hour. Drivers take cues from their surroundings to determine the speed they will drive. Cues that slow drivers include on-street parking, pedestrians, cyclists, buildings built to the street, narrow lanes and trees close to the roadway. Pedestrian activity is akin to the classic riddle of which comes first the chicken or the egg. You will not have significant pedestrian activity until you begin to slow cars with the other cues. Once the cars begin to slow then the pedestrians will come and further slow the cars which will then bring more pedestrians.

A few advantages of the street section with parking in the middle of the street compared to a three lane section with parallel parking on both sides are:

  • A three lane section would only provide minimal on-street parking due to number of conflicting driveways on S. Dixie Highway. Providing parking in the middle of the street solves this problem.
  • Placing the trees in the middle, versus on the outside curb side, provides a superior tree canopy that doesn’t interfere with overhead utilities. There will be no need to give trees an ugly haircut to avoid the power lines.
  • Parking in the middle provides edge friction and visually the street appears narrower than the wide open three lane section with parallel parking. Wider streets without edge friction = higher car speeds.
  • The median area can be configured to have pedestrian Ramblas areas as shown here:
Lancaster Boulevard - Ramblas
Lancaster Boulevard – Ramblas

The center median also functions well for community events such as farmers markets and art shows as shown here:

Lancaster Boulevard
Lancaster Boulevard

In summary, providing parking in the middle of the street is the only option that can immediately provide the necessary cues to drivers that they are entering a place and are no longer on a high speed urban arterial. A three lane design with parallel parking will not be effective with the existing driveways and overhead electrical lines.

The middle parking ramblas is not appropriate for all of S. of Dixie Highway. It is recommended that this design be placed in two to three block groups spaced at a 1/2 mile. Two to three blocks make a destination. These blocks would serve as mini villages much like the commercial nodes found at stops along early twentieth century streetcar suburb lines. The mini-villages would be where nearby residents could walk for a cup of coffee, meet friends for dinner, or pick up their dry cleaning. These blocks would be placed equidistant in the north-south direction between the major east-west arterials such as Forest Hill, Southern, and Belvedere. A half mile spacing is suggested since people are typically willing to walk a ¼ of a mile.

An obvious question will be how can a four lane road be turned into a two lane road? First, it is important to understand that a four lane road in an urban area with high amount of access points doesn’t make effective use of all four lanes since the inside lanes serve as de facto left turn lanes. By only providing these two to three block mini villages at half a mile increments it is possible to keep five lanes at large signalized intersections such as Forest Hill, Southern, and Belvedere and have traffic merge down to the mini-villages. A single lane in the mini-village has a capacity similar to two lanes at the large intersections with traffic signals. This is because of the limited amount of time available for all the conflicting traffic movements at the large intersections with traffic signals.

Intuitively the amount of traffic along S. Dixie is not constant. It is reasonable to assume that there is less traffic on S. Dixie as you move away in the north or south directions from the east-west arterials that connect to I-95. By placing the mini-villages halfway between the east-west arterials the amount of traffic passing through the mini-villages is minimized. Drivers whose destination is near the east-west arterials will not experience any delay from the mini-villages. For someone with a longer drive say from Lake Worth to downtown West Palm Beach the additional delay would be a small amount on their overall trip. We also need to consider that the number of trips a road experiences isn’t a zero sum game. Roads experience a phenomenon called induced demand. Induced demand is when the supply of something is increased (like roads) people actually use them even more. A great example of this is the TED talk on Stockholm Sweden’s experience with congestion tolling of roads. The takeaway is that when Stockholm instituted modest congestion tolling at rush hour the traffic dropped by 20%. So 20% of the trips before the tolls really weren’t necessary, but were caused by induced demand from a having a free commodity.

The current four lane road, besides being inefficient at moving cars is also unsafe. This type of  road has a very high crash rate due to rear end crashes that occur when vehicles stop for a left turning vehicle in front of them or sideswipe when changing lanes to go around a left turning vehicle. From a commerce standpoint this type of road is awful as drivers spend their time looking to change lanes around left turning vehicles instead of looking at the businesses along Dixie Highway.

One final point. For many the thought of converting sections of Dixie from a four lane road to two lanes with parking in the middle is far too radical of an idea. There is no way it would work. All the fancy visualizations and well written prose isn’t going to convince them. What should be done is for the City and FDOT to perform a low cost experiment by temporarily installing a few the middle parking mini villages. The Better Block movement has shown how this to provide cost effective temporary installations. Here is a video of a better block project:

Lancaster Boulevard


  1. I like the idea of the center parking. I’m wondering if it would be advantageous to also add street trees or a planter, bollards or some way to provide a separation between the sidewalk and driving lane. I think you would feel better as a pedestrian if there was at least a visual separation between the sidewalk and driving lane. Even if car speeds are lower. Parallel parked cars typically provide that.

    • Baron Haussmann

      I agree. Trees on the outside could be placed in tree grates which would leave sufficient width for the sidewalk. The overhead electric lines on the one-side of the street aren’t cheap to place underground, but if the road diet was successful then property values would increase enough to pay for the undergrounding of the overhead utilities.

  2. Pingback: South Dixie, Waterfront plans depend on protected bike lanes | Walkable West Palm Beach

  3. Pingback: South Dixie, Waterfront plans present opportunity to implement protected bike lanes | Walkable West Palm Beach

Leave a Reply

Your email address will not be published. Required fields are marked *