Parking lot islands

[tulsa]

Hey guys and gals, I am new to the forum. Well, actually I've lurked for quite some time but am just now registering. I have a question for all of you brilliant minds.

I am a planner in a small exploding burb of, you guessed it, Tulsa. Our zoning ord's are minimal at best however evolving. We just had a large shopping center go through a site plan review and in that review our PC required the developer to install landscaped islands around the parking lot light poles. We do not have a code requirement specifically for these however staff defended the PC requirement with a broad statement from the code - something about ensuring proper circulation.

There is some conflicting views related to these islands and their necessity within city hall. My boss and I argued the aesthetic and protective (light pole and auto) issues to death and we are going to enforce the requirement but I was wondering if any of you can provide me with more good reasons for requiring landscaped islands around parking lot lights within a gargantuan parking lot?

[zman]

First, landscaping allows a different view from just an ugly mass of pavement, but also would dress up the development to attract tenants (to be told to the developer if he does not like the requirement). From a safety standpoint, I would at least say that the plantings on the ends of the islands must only reach a height of 24 inches to allow for proper sight lines for cars turning.
Basically in cities I've worked in, it is required just for asthetic purposes. If the site becomes vacant, as an old KMart did in my previous location, not having landscaping in the parking lot helped it remain vacant for about 5 years and counting and scarred that area of town with an ugly piece of cracked pavement.

[Cardinal]

You hit on a big, practical one with light poles, but I would encourage you to broaden the requirement. My last employer required a landscape island for every twenty stalls. Properly located, landscape islands channel traffic and reduce the tendency for people to cut across parking lots, which leads to accidents. They can be used to help create protected pedestrian access across the lots. Aesthetically, they help to break up the expanse of asphalt and add some greenery to the lot. Environmetally, landscaped islands can reduce the 'heat island' effect. They can be incorporated into storm water management plans. They can provide areas for snow storage.

[NHPlanner]

From my town's regs:

g. Mitigating the impacts of parking lots:
1. As a supplement to the parking lot landscaping standards contained in the Zoning Ordinance, a minimum percentage of the overall interior area of a parking lot (as measured by the exterior perimeter) shall be dedicated to landscaped areas (to be included on the landscape plans) with ground cover, shrubbery, and trees, as appropriate, as follows:
i. 10% on parking lots located in front of the principal building or on otherwise vacant lots.
ii. 8% on parking lots located on the side of the principal building, set back from the front boundary line at least even with the front of the principal building.
iii. 5% on parking lots which are located at the rear of the principal building and largely obscured from the road.
2. Landscaping within parking areas shall provide visual and climatic relief from broad expanses of pavement and shall be designed to channel and define logical areas for pedestrian and vehicular circulation.
3. Internal parking lot landscaping, as required by item 1, above, shall contain one deciduous shade tree for every 15 parking spaces. Trees shall be distributed throughout the parking lot as evenly as possible. Trees shall be set back at least 5 feet minimum from the face of the curb. Tree placement and parking lot lighting shall not conflict. Interior parking lot landscaping may be waived in truck parking areas provided they are screened and perimeter plantings, as described in items 5-7 below, are provided.
4. All landscaped areas shall be protected from encroachment by vehicles by curbing, landscaping timbers, curb stops, or other acceptable means.
5. Shade trees shall be provided around the perimeter of all parking areas at a minimum ratio of 1 tree per 20 feet of parking lot perimeter. In portions of parking areas where screening is required, shade trees shall be provided along the perimeter at a minimum ration of 1 tree per 50 feet of parking lot perimeter in addition to the required screening. Trees may be clustered or grouped, if desired, as long as clusters/groups are not more than 75 feet apart.
6. All off-street parking areas located at the front or side of principal buildings or on vacant lots shall be screened from the public right-of-way with appropriate screening, as described in Section 3.09e, to provide at least 50% vertical opacity on average up to a height of 3-1/2 feet above grade, excluding sight distance areas at vehicular entrances and exits. If vegetation is used a hedge should be planted which is reasonably expected to reach this opacity and height within 1 year. If non-vegetative materials are used, appropriate ground cover, shrubs, and trees shall be planted (or retained) within the front area to soften the development.
7. Screening from Residences: All off-street parking areas shall be screened from abutting residences or vacant lots in residential zoning districts (AR-I and R-III) located at the side or rear of the property with a wall, fence, vegetation or other means which provides at least 75% vertical opacity up to a height of six (6) feet above grade. If vegetation is used a hedge should be planted which is reasonably expected to reach this opacity and height within one year (see Section 3.09e).

[biscuit]

One of the best, and strictest, parking lot regs I've seen belongs to the town of Mt. Pleasant, South Carolina. I don't remember exactly the way it was worded but the crux of it was a requirement for X sq.ft. of shade tree coverage for every Y sq.ft. of parking lot surface, or something along those lines... I'll look in my files for it when I get home.

[landon]

I'll share the requirments.

10 square feet of landscaping for every 100 square feet of parking lot.
Each parking island has to be at a minimum of 200 square feet.
No more than 20 parking spaces in a row.
10 ft landscape strip adjacent to right-of-ways (does not count for traffic "island" square footage).
One "shade tree" for every 50 feet of frontage along right-of-way, and One "shade tree" for every 100 square feet of interior landscping or landscape island.

Also, give credit if developers are willing to save existing trees and designing the parkin lot around the existing features.

Why have them? --- We'll the ideas already stated above are good one's, But I have a question:

My community is located in the southeast where Oak trees are seen as having cultural and historical signifigance -- therefore the leaders of the community are eager to protect them -- do any of your communities share these ideas?

[zman]

Being in drought ridden Northern Colorado, we are aupposed to use native-water conserving trees and plants. Trouble is on the high plains, native means very few trees. The term Xeric Landscaping gets tossed around, but my city does not have specific requirements, although I try to push certain species/types.

[ludes98]

Most cities in our area have island requirements for the mitigating reasons mentioned already. Usually at the end of parking rows and spaced about every 10-12 spaces. These would be full length islands equal to the depth of the parking stall and about 300 sqft for double rows or 150 sqft for single rows. Some cities here also have additional parking diamonds every 3-6 spaces. These are small 5'x5' islands that preserve spaces but allow many small trees.

On a separate note (JNL would appreciate this one) but you may want to consider it a safety issue to separate trees from light poles. On a recent project, the city has CPTED regs that require a 20' separation to keep trees from interfering with the reason for the lights to exist in the first place. The concrete base often poured for lights is usually 3' high and protects them from vehicular damage, but perhaps this is specific to our area.

[DennisMaPlanner]

I agree with everything that has been posted here. We require 1 tree for every 5 parking spaces. Having these in the parking lot reduces the heat island affect of the parking by providing significant shading. I would think this would be a strong argument anywhere.

When I worked in NH I once did a project review for an expansion of a movie theater at a shopping mall. I found that the after hours accidents in the mall parking lot (no islands) were more in number and more serious (including fatals) than on many of the area roads. An adjacent mall had a much lower accident level and severity rating due in large part to the islands and channeling.

[ablarc]

Promotes sprawl. Lipstick on a pig.

[ludes98]

Promotes sprawl. Lipstick on a pig.

I like the analogy.