Removal of Street Trees for Road Re-paving 3

[Mechie10]

The township engineer wants to remove street trees on a residential street that is to be re-paved with asphalt. This seems to be a drastic step and many surrounding municipalities have still kept their old growth street trees. He claims the tree roots are mis-aligning the curbs and undermining the pavement and fracturing it. However, the asphalt fractures are located down the length of the street not isolated near the trees. The curbs are mis-aligned near the trees. The trees are Sycamore, measure about 10" diameter, 30 ft high and are about 40 years old. The are planted between a 24" strip between the curb and sidewalk. As part of the the street reconstruction, additional storm sewers were added to prevent standing water caused by poor drainage. Shounldn't the construction of the old street be checked (possibly a core sample) to determine that that is not the cause of the fractures. Is tree removal a accepted practice when re-paving a street?

 

[cvg]

I would be more inclined to agree with the township engineer, but this may be a case where a public meeting should be held because if you cut down all the trees, there will probably be a lynch mob looking for you to hang you from the nearest tree (if there are any left standing)...

 

[PELS]

Sycamore trees are known to have an aggressive root system that can wreak havoc on sidewalks and pavement:

http://www.arborday.net/Trees/TreeGuide/TreeDetail.cfm?ID=120

They have large dense leaves that provide excellent shade when full grown, however unlike many trees, their leaves do not break down (they remain intact) and create many problems with clogging drain inlets, not to mention the maintenance issues with clearing them in the fall season. Many cities like to plant them for street trees because they grow very fast and give the street the shade and look that most people like to see when driving down the street.

My recommendation would be to have an arborist provide a report on the condition and future prospects of each tree. Those that appear to be causing problems with mis-aligning curbs should be removed and those that are not causing problems can be retained. Since they are fast growing, planting new trees may help to assuage the environmentalists. Perhaps a few different species would help break up the monotony as well. Maybe give the lot owners some choices so they are a part of the solution.

 

[bridgebuster]

Well let me add my $0.02: In NYC, (which does a lot of paving on residential streets)you need a dispensation from the Pope to cut down a tree. NYCDOT requires an arborist on every street job in order to trim the tree roots. If that can't be done, the curbs and sidewalks are often modified to accommodate the tree.

Illegaly removing a tree in NYC can cost the guilty party upwards of $25,000 per tree.

Recently in a nearby town where I live, the town removed a lot of old growth trees, well, the town council caught hell for it and now thy're spending a lot of money replacing those trees - out of fear for losing their jobs.

 

[fattdad]

Leave the trees alone!

f-d

¡papá gordo ain’t no madre flaca!

 

[ACtrafficengr]

Part of the problem with tree roots is compacted subgrade. Roots have trouble moving through the material, so they spread just below the sidewalk or pavement slab. This causes faulting. The Cornell University Department of Horticulture has developed CU-Soil, a mix that is structurally sound, yet allows tree roots to propagate through it without nearly as much upheaval. You can find more info here:

http://www.hort.cornell.edu/uhi/outreach/csc/

You don't mention how fast people drive on this street. At higher speeds, trees over 4" in diameter are hazards, should a driver run his vehicle off the road and hit one. In fact, the only thing more dangerous to hit than a tree is an unprotected bridge abutment.

On the other hand, some people that opine that on neighborhood and downtown streets, the presence of trees and other roadside amenities encourages slower traffic and thereby increases safety. I'm not aware of any definitive studies proving this is true or untrue.

"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

 

[tsgrue]

.

There are several studies available regarding street trees and sidewalks/pavement. Live Oaks tend to be one of the best for such areas in many situations. Try some W3 engine searches and you'll get lots of hits - especially for urban forestry resources.

.



tsgrue: site engineering, stormwater
management, landscape design, ecosystem
rehabilitation, mathematical simulation

http://hhwq.blogspot.com

 

[Mechie10]

"You don't mention how fast people drive on this street. At higher speeds, trees over 4" in diameter are hazards, should a driver run his vehicle off the road and hit one."

There is a 25 MPH limit on the street which is suburban residential zoned. So I would think speed should not be an issue. Traffic frequency and load is relatively light as well.

As part of the reconstruction the street trees will be replaced, but the variety is not known at this time. Residents were not happy with previous replacements because they were far smaller and very slow growing. I'll check out the oaks and the CU-soil.

 

[GeoPaveTraffic]

Don't cut the trees down.

But if you do, then don't plant new trees that this same engineer is going to want to cut down next time the street needs to be paved.

 

[cvg]

if possible, move the trees back from the road. tree roots can extend well beyond the dripline of the tree. it is likely that since these are planted just a few feet from the curb, that roots extend under the entire roadway. If they can find a waterline leak, gravity sewer or storm drain, they will try and intrude into the pipe, manhole or catch basin.

 

[dicksewerrat]

Shrink the width of the raod. this will slow traffic,save trees and save the job of the engineer.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[ACtrafficengr]

Dick has a good point. What is the existing width?

24" is pretty narrow for a tree strip, and 10" diameter is pretty small for a 40 year old tree. Is there more room behind the sidewalk, or is it an urban area?

"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

 

[Mechie10]

Existing width on the road is 15 ft. Turns out the strip between the curb and walk is 45" and there is 24" available behind the walk by way of an easement. This is a suburban zoning. Using the 24" behind the walk probably won't be popular with the homeowners, but these are the choices. I also found a "root guard system" will be installed around each newly planted tree to prevent root pavement faulting. From a limited amount of research, I found this is barrier to prevent root intrusion under the walk and pavement.