NewUrbanStreets

First, there is a street in Houston named Dallas Street. Plus the title to this article is correct as trees were planted and are growing in the parking lane on one side of that street. I do not know the story behind the street being named Dallas but I can share with you the story of the trees. Some would say this was the boldest experiment with streetscape enhancement and place-making in downtown Houston. I am confident it will be a resounding success as the kinks have been worked out–assuming drivers do not drive over the improved, traffic resistant configuration: i.e bollards.

Dallas Street badly needed street trees for the obvious aesthetic reasons and to provide shade in the summer for pedestrians. But, the sidewalk was not wide enough to accommodate tree wells and basements extended out to the curb line in some of the blocks.  In addition the traffic volume was too great to close a lane and move the parking lane over. And, no one wanted to lose half (one side) of the on-street parking. The solution was to put the trees in the parking lane and drivers would park between them as pedestrians enjoyed the shade and the ambiance of a tree-lined street. This maintained 75% of the on-street parking and the associated revenue.

The challenge was to add the trees in a manner that fit into the streetscape without appearing to be out of place and to do so with a limited budget. The initial concept called for pavers in the lane between the trees but the cost of removing the existing pavement, pouring a concrete sub-slab and placing the pavers was prohibitive. The design was simplified but did create a distinctive lane with white precast concrete dots lining the clean smooth new asphalt lane.

The first step in the installation process was to mill 2-inches of the asphalt street in the curb lane. Then: full-depth saw cut the square are for the tree wells; remove the old broken curb and gutter; place in the curb and gutter location underground conduits and irrigation lines between the tree wells; form the center circle to hold the tree; pour the concrete; plant the trees; place the heavy cast iron grate; place asphalt in the milled areas between the concrete squares; core a shallow 12″-diameter hole evenly spaced where the white traffic control line would go; epoxy in the precast white concrete cylinders in those cores; take down the construction tape and watch the trees grow.

As the originally planned pavers were too expensive and the threat of the required white line would surely not contribute to the uniqueness of the lane, another form of a “white line” was contemplated.  The dots made of a white concrete and recessed in the asphalt was chosen for it’s distinct visual impact and what we we hope will be low maintenance. So far none have split or shattered. The design and installation of the dots is interesting if you like that sort of thing so I will soon post and article with details of how it was done. We even placed them in existing concrete unit paver crosswalks.

The question from the beginning was will the trees be damaged too frequently as surely someone will sooner or later hit one–or two. I was surprised how frequently they were hit as other drivers must not care about dings in their bumper like me.  The damage was primarily bumps when cars were backing into the spaces but that was enough to leave the cage bent over pressing on the tree trunk. Bending it back was not easy nor restored the original appearance.

The worst case of damage resulted from a large vehicle, likely a delivery truck, that flattened the cage and tree in almost a comical fashion. The pessimists that said trees in the lane would never work would say this photo is what will happen everywhere-but that is not true. This location how has bollards.

By now you want to ask why were bollards not installed. The decision was made to not installed them although the design of the concrete provided a place for them. The installation is much more appealing without them and there was hope that drivers would avoid hitting the cages. But drivers did not seem to mind bump them hard enough to bend them over–so bollards had to be added in the high-traffic areas. The bollards installed are the typical 6-inch diameter, concrete filled steel pipes painted green with a white reflective tape around the top.  Given the driver’s willingness to hit the cages the decision to use a classy bollard would have also been a costly mistake.

Notice in the last photo with the bollards the up-lights below the grating as this photo was taken early one morning.

As I write this post the trees are budding out so check back in a few months for photos of a tree-lined Dallas Street in Houston Texas.

I want to acknowledge the determination of Patrick Hood-Daniels–the Director of Planning for the Houston Downtown Management District at the time of this project–who promoted this concept and lead the design.