LCHQ is an advanced design guide for professional landscaping.
Every time you create a roadside landscape design, you need to do a quick check of a few things before starting. It’s surprising how nicely this pulls together your concept and moves you toward a great design! By checking these items initially, you can map out the basic configuration of use zones, which develops the structural framework from which your design can be based. Sometimes, after doing this, a shape calls out to you. Block out zones for setbacks, vertical clearance, overly steep slopes, clear sight lines, sign visibility, guard rails, and utility easements to keep your landscape design free of safety conflicts. Consider the following items your first priority.
• Setbacks and the Clear Zone
Keep any tree you propose on public rights of way well beyond the required safety clear zone to avoid creating a fixed object that might be hit by an errant driver that runs off the road. This gives the driver an opportunity to recover and get back on the road without injury or damage to the vehicle.
• Tree Canopy Clearance
Leave an adequate vertical space open along the road travel way to avoid overhanging branches from slapping against panel trucks driving near the edge of the road.
• Slope Steepness
Plant material can barely establish on slopes steeper than 3:1, and mowing on steeper slopes is not possible to do safely. The clear zone doesn’t exist for slopes steeper than this.
• Sight Lines
Drivers need to be able to see oncoming traffic when they attempt to turn into or cross over public roadways. It is the designer’s responsibility to keep sight lines open.
Keep view zones for directional and advertising signs free of vegetation that will grow to obscure the signs.
As tempting as it may be to soften guardrails with picturesque vines, they must be kept visible at all times.
Work with local utility companies to avoid conflicts with overhead and underground utilities when planting vegetation. Utility companies will remove any plants within their easements that threaten their lines from working properly, and the result is not always pretty.
You can find more information about trees in The Advanced Guide to Roadside Design: How to Create Successful Public Landscape Projects, part of The Advanced Guide series.
When you finish marking out the clear zone areas and add open sight line triangles on your plan sheets, you see shapes taking place for your landscape design that can guide your design direction.
You can see how impactful the clear zone, utilities, signs, slopes, and sight lines are to your design! You might even say the conflicts with these restrictions leave no area for you to landscape. An experienced landscape architect will tell you all great landscapes have challenges that must be overcome. This is where your creativity and innovation are sparked. Elevated design in the real world transforms challenges into defining inspiration. Use these challenges to build your skills.
I have seen some design firms choose to argue for variances and political favors to push forward with landscape plans that would have benefitted from innovative revision. The easy designs resulted in sub-standard outdoor experiences. Make your design work within the safety obligations. Real fun and satisfaction in your life’s work come from constructing a legacy for others to safely enjoy long-term.
You can read details on how best to deal with plan design safety criteria in The Advanced Guide to Roadside Design; How to Create Successful Public Landscape Projects.