Question
Marc,
Thanks for all the info! It will be a great help! I live in Rhode Island, can you provide a co-op website for me to find out more info on plants/shrubs in my state?

I thinking about taking your advice on putting a 6 ft stockcade fence up along the wooden area that's the buffer between my yard and the highway. Do you have any more suggestions on how to enhance how the fence looks with plants or shrubs? As I mentioned, I don't think whatever I plant will get a lot of sunlight. Or if you can offer any more ideas on what type of fence I should use, it will help me narrow down my search, thanks!

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Followup To
Question -
Marc,
I live in New England, there is a major highway that runs along the back of my house. Right now the buffer between the highway and my back yard is mostly a wooden area. There are some open spaces during the summer months and of the tree loose their leaves during the winter months, so it is pretty noisy during the winter. Can you suggest any bushes, trees or shrubs that I can plant to fill up the spaces and maybe provide more of a buffer during the winter? My concern is that whatever I plant may not get enough sunlight, thanks for your help.
Answer -
As far as the Visual aspect of living next to a road, here are some suggested plants for your area  - Since you live in New England, you'll have to look for hardier plant materials:

Japanese Boxwood - Buxus japonica 'winter jem' (good to -10)
Dwarf Alberta Spruce
Juniper (many types - consult a local nursery for size-appropriate
variety for your area)
Yew - Taxus
Arborvitae ?Thuja

For the bigger evergreen trees or for other plants that work well in your region, consult your local Cooperative Extension office.  If you give me your State, I can reply here with the appropriate website you can check out for more ideas in your area.

I know that living near a busy road, you;'ll also want to try and "buffer" the sound.  Unfortunatly, there really is no practical way to block sound with plants on a small, residential scale.  Adequate research has not been conducted which demonstrates the effectiveness of plants in controlling sound pollution. A standard road will generate 90 decibels (Db) of noise, whereas a hedge will only attenuate about 7Db per 100 linear feet of hedge.  And, effective sound control is dependent on the interaction of several factors including: 1) direction, frequency and intensity of noise; 2) topography, wind, temperature and humidity, and; 3) location, spacing, species and density of the plant screen. These interrelationships are complex and unpredictable. Plants have been shown to be most effective at screening the higher, more annoying frequencies of unwanted sound.

Since it sounds like you have a larger lot, I would suggest the use of a 揾ardscape?solution.  Fences, walls, or berms in combinations with plants to deflect the sound up or away from your home.  Road noises generally travels upward, so if you have a slope down to the road or a second story home, the closer to the road you get the wall/berm/plants, the better.  These, in combination with deciduous plants with thick, fleshy leaves have been shown to be most effective in absorbing, deflecting and reflecting noise. Evergreen trees, shrubs, and ground covers can be mixed with deciduous plants to create a solid, year-round buffer. Wide bands of such plantings or a six-foot solid wall covered in Ivy and a 5-foot wide hedge in front will also absorb a lot more sound than a simple hedge of boxwood.   The wider the hedge, the more sound it reduces, as it is the twigs, leaves and branches that "absorb" or reflect the sound back at the source.  There are some really neat examples out there.  Write back if you want more suggestions  (types of fences/walls, how to build a berm, what to plant on it, etc.)

Also consider "masking" the noise with "white" noise, like a trickling fountain or maybe attract some birds to your backyard with seeds or bird-friendly plants.

Hope this helps -


Answer
The Univeristy of Rhode Island Ag Extension home page has several informational brochures for the home gardener and suggestions for trees and shrubs for your area:

http://www.uri.edu/ce/index1.html

Interesting enough, check out the URI website, "Landscape Screening" at:

http://www.uri.edu/ce/ceec/ppprivacyscreening

Be cautious, and find your USDA zone for the right plant at this site:

http://131.128.91.217/maynard_susplants/html_spl2000/usda_zones.asp

For berms, check out the HGTV site:

http://www.hgtv.com/hgtv/gl_design_other/article/0,1785,HGTV_3566_2206578,00.htm

I have used the Eastern White Pine for screening in Virginia, and I'm glad to see that it should grow in your area.  Its my favorite pine tree - delicate, but tough!

Have Fun - Marc