Another strip of pavement? That's what people on this board want?
Well, remember- this trail, when completed, is going to run right smack through the center of Condord, NH, which is a pretty heavily urbanized area. A wide paved trail makes sense in this situation for a variety of reasons.
Visually, the paved trail is unlikely to have a huge impact. It'd be a different story if the trail was planned to run through a more rural area, but we're talking about the capitol of New Hampshire- a population center with nearly 50,000 residents. And with those numbers, given the amount of use that this trail is likely to get when completed, I'd say that pavement makes sense from an economic perspective as well- the higher levels of use are likely to result in significantly more wear and tear to this trail than many other greenways receive.
A paved trail also makes it easier for a wider variety of uses, which are sure to occur in such an urbanized environment. Roller-blading is sort of a thing of the 90's, but some people still do it. Plus you've got the folks that use the skis-on-wheels for x-country training when it's not winter- it'd be a lot easier for them to use a paved trail. And a paved trail is a heck of a lot easier for those confined to wheel chairs to use than a dirt or gravel trail is.
From an ecological perspective, with a trail that will be used as much as this, dirt or gravel are unlikely to provide any greater level of ecologic protection, and may actually result in a greater level of ecological impact from the trail. Dirt or gravel would become significantly impacted from use, and you're likely to see greater levels of runoff as a result- rainwater will simply be incapable of percolating through the surface of the trail. And with that runoff, erosion and sedimentation of nearby waterbodies is going to be a significant concern along the trail. In fact, a paved trail that uses some of the newer types of pavements available that allow for rain water percolation might have a greater level of percolation than a gravel or dirt trail would. Believe it or not, a well-planed and constructed paved trail in an urbanized area could be more ecologically friendly than a dirt or gravel trail would be.
As for the width of the trail, again, it's more than likely that this is due to the level of use that the trail is likely to receive, and probably stems from safety/visibility concerns. With a combination of both fast and slow activities (biking vs. walking) occurring, and 2 way traffic present on the trail, you're going to want enough space for people to pass in the center. This way, a biker can safely overtake a jogger in one direction, without having to worry about impeding traffic headed in the other direction.
Building a trail is often times very similar to building a road. This is especially true when it comes to urban greenways that are likely to receive high levels of use and impact. And, just like with road construction, there are actually standards for trail construction- how much to rainbow the cross section of the trail to facilitate sheeting of runoff, width based on the likely amount of use, when to use pavement vs. gravel vs. dirt, maximum incline, etc., that are all based on years of experience and research in the matter. I'm sure that the decision to make this a paved trail was not made lightly, especially given how much it will cost!
