Cutting down trees from highway medians

[golden eagle]

On recent trips to the Gulf Coast, I saw where a lot trees on U.S. 49 between Hattiesburg and Gulfport were cut down. The same happened on I-59 in Pearl River County and recently, trees have been cleared on I-20 in the Pearl area. Is this being done as a safety issue and are other states doing the same thing?

[Quillz]

I'd imagine it's most likely a safety issue. I'd assume that if a car was to lose control and slip into the median, it'd be better to land on just open dirt rather than hit into a tree.

[NE2]

It's possibly in preparation for installing cable barrier? (Since it is better to hit a tree than to hit oncoming traffic...)

[Urban Prairie Schooner]

I believe this is being done so that trees will not fall into the freeway during a hurricane or other severe tropical weather.

[froggie]

It's possibly in preparation for installing cable barrier? (Since it is better to hit a tree than to hit oncoming traffic...)

Not in these cases.

UPS has probably the closest answer.  As I understand it from when MDOT was clearing out I-59, FHWA requires a 30ft clear zone, but MDOT has been going with a 70ft clear zone.  The safety issue has some to do with it (I recall a particularly nasty fatal outside Meridian on 20/59 some years ago), but a lot of folks think MDOT has gone overboard with it.

[realjd]

I'd imagine it's most likely a safety issue. I'd assume that if a car was to lose control and slip into the median, it'd be better to land on just open dirt rather than hit into a tree.

Hitting a tree is better than hitting oncoming traffic...

Until they put cable barriers/cement barriers in recently, my part of Florida had a very significant problem with head-on collisions on I-95. The old-timers here said that I-95 used to have trees in the median (similar to Volusia County to the north) back when it was new, but people complained that not seeing oncoming headlights made them sleepy, so they cut them down. Again, this is just talk, I don't know if there's actually any truth to that.

[Alps]

70 is ridiculous.  The Garden State Parkway went to 30 feet not too long ago (from maybe 10 feet tops).  The result looks a lot more like a freeway and a lot less like a parkway.  For the one tree every ten years that may fall onto the roadway, we're sacrificing so much natural beauty.  "But you could save that one life!"  I've been an engineer too long, because everything has its price, and that's true for lives and beauty as well...  People will love to disagree with me on this...

[froggie]

70 is ridiculous.

That's exactly what folks in Picayune and Pearl River County (myself included) were saying a few years ago when they cleared out I-59.  But MDOT has a long and colorful history of bulldozing its way through, and local opinions be damned...

[jjakucyk]

70 is ridiculous.  The Garden State Parkway went to 30 feet not too long ago (from maybe 10 feet tops).  The result looks a lot more like a freeway and a lot less like a parkway.  For the one tree every ten years that may fall onto the roadway, we're sacrificing so much natural beauty.  "But you could save that one life!"  I've been an engineer too long, because everything has its price, and that's true for lives and beauty as well...  People will love to disagree with me on this...

I'd tend to agree with you on this.  It'd be interesting to see a study if actual speeds increase after cutting down so many trees due to people's perception of improved safety.  Wide-open expanses of grass are so boring compared to forested areas, plus the woods help cut down on cross winds and summer heat to some extent (though admittedly the tree canopy rarely develops to the extent that it can shade an interstate directly).

Something that seems effective, and which I'm surprised we don't see more, is a raised median.  As opposed to a gentle slope to a ditch in the middle, it's sort of a triangle in section, with a small ditch on each side.  I can understand that it complicates the drainage somewhat, but it seems like a mound of dirt can pretty effectively block crossover traffic and allow trees to grow closer to the road without safety risks. 

[golden eagle]

70 is ridiculous.  The Garden State Parkway went to 30 feet not too long ago (from maybe 10 feet tops).  The result looks a lot more like a freeway and a lot less like a parkway.  For the one tree every ten years that may fall onto the roadway, we're sacrificing so much natural beauty.  "But you could save that one life!"  I've been an engineer too long, because everything has its price, and that's true for lives and beauty as well...  People will love to disagree with me on this...

I'd tend to agree with you on this.  It'd be interesting to see a study if actual speeds increase after cutting down so many trees due to people's perception of improved safety. 

I tend to drive faster in areas with treeless medians because I don't have to worry about cops hiding and catching me speeding.

[Sykotyk]

70 is ridiculous.  The Garden State Parkway went to 30 feet not too long ago (from maybe 10 feet tops).  The result looks a lot more like a freeway and a lot less like a parkway.  For the one tree every ten years that may fall onto the roadway, we're sacrificing so much natural beauty.  "But you could save that one life!"  I've been an engineer too long, because everything has its price, and that's true for lives and beauty as well...  People will love to disagree with me on this...

I'd tend to agree with you on this.  It'd be interesting to see a study if actual speeds increase after cutting down so many trees due to people's perception of improved safety.  Wide-open expanses of grass are so boring compared to forested areas, plus the woods help cut down on cross winds and summer heat to some extent (though admittedly the tree canopy rarely develops to the extent that it can shade an interstate directly).

Something that seems effective, and which I'm surprised we don't see more, is a raised median.  As opposed to a gentle slope to a ditch in the middle, it's sort of a triangle in section, with a small ditch on each side.  I can understand that it complicates the drainage somewhat, but it seems like a mound of dirt can pretty effectively block crossover traffic and allow trees to grow closer to the road without safety risks. 

Or it could produce an effective ramp for those surprise aerial assaults of the opposing traffic.

[mightyace]

Or it could produce an effective ramp for those surprise aerial assaults of the opposing traffic.

Watching a lot of "Dukes of Hazzard" haven't we? 

[Jim]

It has to be 15 years ago now that New York took out tons of trees from the median on the Northway (I-87) north of Albany, maybe up into Saratoga County or even up toward Glens Falls.  I think it took a lot away from that stretch of highway.  I don't remember hearing a reason but I assumed at the time it was a safety concern.

If you want the complete opposite, try the Taconic State Parkway.  Trees just off the shoulder, in the median, you'd think one might pop up in the left lane at any moment.  More than once, I've seen a car stuck in the branches of the trees in the median.   Very scenic drive, though.

[njroadhorse]

I tend to drive faster in areas with treeless medians because I don't have to worry about cops hiding and catching me speeding.

I agree with you here.  In a way, large clear zones make our lives easier with that, but 70 is too big, and honestly, any size clear zone would work for driving higher speeds.

[LeftyJR]

The northern part of the Allegeny Valley Expressway (PA-28) had most/all of its pine trees removed in 2007 - between exit 17 and U.S. 422.  It was very beautiful, now its just boring.

[jwolfer]

On recent trips to the Gulf Coast, I saw where a lot trees on U.S. 49 between Hattiesburg and Gulfport were cut down. The same happened on I-59 in Pearl River County and recently, trees have been cleared on I-20 in the Pearl area. Is this being done as a safety issue and are other states doing the same thing?

When GA widened I-95 in Camden County a few years ago the median trees were removed.  Not enough clear space.. I always liked the way a treed median looks... But I can see the safety concerns

I-10 in west of Jacksonville is mostly treeless medians except for the Osceola National Forest

[agentsteel53]

I-10 in west of Jacksonville is mostly treeless medians except for the Osceola National Forest

I remember the vast majority of it as being quite treeful - you cannot see any other lights; neither towns, nor the headlights of traffic in the opposite direction.  it makes the area seem very desolate, even though it isn't at all: there's lots of small towns on US-90 just a couple miles away.

[Sykotyk]

I-95 in Maine was butchered from Bangor to the Canada line a few years ago.  In some places, there was a row (sometimes two wide) of trees down the middle. They also cut back the trees from the shoulder that was already far away from the road.

I assume this was to better see Moose and try to keep them away from the road as they wouldn't be in a wooded area then. Still, such a loss.

[D-Dey65]

Or it could produce an effective ramp for those surprise aerial assaults of the opposing traffic.

Watching a lot of "Dukes of Hazzard" haven't we? 

No, sometimes these things are true. In any case, FDOT claims they want to widen I-75 in Pasco, Hernando, and Sumter Counties, and I think they should. But there are segments where the median is widened and some of those widened segments contain trees. I think they should have more of them, but unfortunatley the widening plan calls for tearing a lot of them down.

[roadfro]

I don't have an AASHTO design guide in front of me, but I'm fairly certain that a clear zone of 50-70 feet is reccommended for freeway grade facilities. ("Clear zone" being defined as an area clear of anything that is not crashworthy, such as guardrails, impact cushions, or signs on crash worthy supports.)

[Alps]

I don't have an AASHTO design guide in front of me, but I'm fairly certain that a clear zone of 50-70 feet is reccommended for freeway grade facilities. ("Clear zone" being defined as an area clear of anything that is not crashworthy, such as guardrails, impact cushions, or signs on crash worthy supports.)

30 feet is the minimum before installing guide rail.

[brownpelican]

It's possibly in preparation for installing cable barrier? (Since it is better to hit a tree than to hit oncoming traffic...)

From what I've seen, cable barriers were installed where the median is narrow/somewhat narrow with NO trees (think most of the interstate system in South Carolina, I-12 in parts of St. Tammany Parish, parts of I-10 between Laplace and Airline Highway).

And yes I think MDOT has gone overboard with their tree clearing, especially on U.S. 49.

[Crazy Volvo Guy]

Something that seems effective, and which I'm surprised we don't see more, is a raised median.  As opposed to a gentle slope to a ditch in the middle, it's sort of a triangle in section, with a small ditch on each side.  I can understand that it complicates the drainage somewhat, but it seems like a mound of dirt can pretty effectively block crossover traffic and allow trees to grow closer to the road without safety risks.

See: Pennsylvania Turnpike spur routes. (Most notably 66, 43)

[wriddle082]

Something that seems effective, and which I'm surprised we don't see more, is a raised median.  As opposed to a gentle slope to a ditch in the middle, it's sort of a triangle in section, with a small ditch on each side.  I can understand that it complicates the drainage somewhat, but it seems like a mound of dirt can pretty effectively block crossover traffic and allow trees to grow closer to the road without safety risks.

See: Pennsylvania Turnpike spur routes. (Most notably 66, 43)

I believe I've also seen this in Ohio on I-71 b/w Cincinnati and Columbus.

Incidentally, for a while I had been thinking that Tennessee's freeway clear zones were 5-10 feet, but it was mainly neglect.  I-40 in the vicinity of the Cheatham/Davidson Co. line has a wide wooded median with a small creek running through it, and it seemed like they let the trees get right up next to the guardrails.  Plus it's on an incline, it's a heavy truck route, and it has a gradual curve, so sometimes traffic would slow down to 45-50 during morning rush hours for absolutely no reason other than motorists couldn't see "far enough ahead".  Also, the weekend that Katrina happened back in 2005, I had to go in to work at 4 AM and I nearly hit a tree that fell onto the right-hand lane!

TDOT recently trimmed the trees back to what seems like 15 feet, and IMO despite the problems they probably shouldn't go back any more since it is a somewhat scenic area.  They also recently cleared out every one of the trees at the nearby McCrory Lane interchange, making it much safer to negotiate (but they possibly are preparing for future interchange improvements).

[Sykotyk]

Something that seems effective, and which I'm surprised we don't see more, is a raised median.  As opposed to a gentle slope to a ditch in the middle, it's sort of a triangle in section, with a small ditch on each side.  I can understand that it complicates the drainage somewhat, but it seems like a mound of dirt can pretty effectively block crossover traffic and allow trees to grow closer to the road without safety risks.

Former PA60/Current I-376 has raised medians for large stretches, actually. They're raised very high (10+ feet). They're a nuisance because, as mentioned, you can't see if there is a cop hiding in a crossover (which they love to do on that road if/when they're actually patrolling that road). It also cuts down on the scenery as you can only see that big mound of grassy dirt on your right half the time.

[Fixed quoting. -S.]