Highway noise goes right through vegetation. Here the highway department has built high concrete walls between some urban neighborhoods and the freeway.

Hard for non solid objects to block noise, use white noise of poplar leaves at least does better than most trees, plant some evergreens also for the visual blocking of them, too, that at least makes it out of sight out of mind.

A land wall like a levee along the road can deflect some noise. Trick is creating one that does not cause drainage issues or create an eye sore.

Hello Rylie,welcome to GardenWeb. I hope you plan on sticking around to get aquainted and share your experience with the other members. A native tree is your best choice. I believe what the locals refer to as "cedar",is perfect. For benifit of the ever present tree police,I'm talking about Juniperus virginiana ��" its common names include red cedar, eastern red-cedar,[2] eastern redcedar, eastern juniper, red juniper, pencil cedar, and aromatic cedar. I suggest you find a dense stand near a busy road and walk among them to see wherther noise is reduced to an exceptical level. Planting trees on an earth levee farthur enhances noise blocking effect. Carrying it a step farthur,placing fieldstone and bolders on the side faceing traffic deflects alot of sound upward and adds a pleasing visual effect. The cherry on top is wildflowers amoung bolders. The one and only enemy is bagworms which are easy to control with a single well timed spray if they become a problem. Roadside fires are common but cedar will spring right back good as new within a year or two. You will find many landowners willing to give you all you want just for the digging. Regardless of your desision,take time to let us know how it works out and we love pics around here.

Juniperus virginiana sucks up a lot of water and creates massive allergen pollen bursts...so I personally wouldn't ever plant any of them. Their main benefit though would be that they are evergreen.

I would suggest creating a mixed hedge sloping up in height away from the highway of "higher value" shrubs & trees like:

<a href="http://www.gardeningknowhow.com/ornamental/trees/wax-myrtle/wax-myrtle-care.htm">Wax Myrtle</a> (as your primary hedge plant:

<img src="http://www.sharptreefarm.com/Wax%20Myrtle%20-%2030%20Gal%20-%208-9%27.jpg">;

& accent hedge with:

Jujube (shrub)

<img src="http://www.veggiegardeningtips.com/wp-content/uploads/2007/11/jujube-tree.jpg">;

Black Chokeberry (shrub)

<img src="http://imagehost.vendio.com/a/35088526/aview/TN281-2.JPG">;

Black Beauty Morus nigra (tall mulberry shrub)

Elderberry (large shrubs)

<img src="http://www.uwgb.edu/biodiversity/herbarium/shrubs/samcan_aspect01.jpg">;

Rusty Blackhaw (tall shrub)

<img src="http://www.floridata.com/ref/V/images/vibu_ru1.jpg"><img src="http://www.beautifulwildlifegarden.com/wp-content/uploads/2011/03/DSCF5994-500x449.jpg">;

Pomegranate (medium tree)

<img src="https://idisciple.blob.core.windows.net/idm/Under-the-Pomegranate-Tree.png">;

Vitex agnus-castus (large shrub & great pollinator attractor!)

<img src="http://www.tree-land.com/images/Vitex_Mature.jpg">;

<a href="http://www.lazyssfarm.com/Plants/Shrubs/Cl-It%20Shrubs/Cl-It%20Images/hamamelis_intermedia_primavera.htm">Hamamelis x intermedia 'Primavera'</a> (large shrub)

<img src=http://www.lazyssfarm.com/Plants/Shrubs/Cl-It%20Shrubs/Cl-It%20Images/Hamamelis%20x%20intermedia%20%27Primavera%272.jpg">;

Goldenball Leadtree (small tree)

<img src="https://c2.staticflickr.com/4/3513/4572178690_102bfb25ab.jpg">;

Eve's Necklace (small tree)

<img src="https://aggie-horticulture.tamu.edu/ornamentals/natives/TREES/SOPHORAAFF1457.jpg">;

Magnolia (Star, Southern, Saucer) trees

<img src="http://www.jimwhitingnursery.com/images/feat-magnolia-royalstar-sm.jpg">;

Redbud trees

Mid-sized Oriental & taller American Persimmon trees

<img src="http://www.burpee.com/images/product/prod003352/prod003352_alt3_lg.jpg">;

Pecan trees

Western Soapberry trees

Oriental Raisin trees (Hovenia dulcis)

<img src="http://plants.ces.ncsu.edu/static/plants/plant_images/hovenia_dulcis.jpg">;

Norway spruce (Picea abies) is really the best tree you could use for quick growth and visual screening.

Thuja x Green Giant is another you may consider.

Dax

The only magnolia in above photo is star magnolia, clipped into balls. "Eve's Necklace" looks like a Robinia.

bboy - I'd not heard of Eve's Necklace. I Googled and found Sophora affinis. Check out those black fruit. Not like the pods of Robinia.

Here is a link that might be useful: Sophora affinis