Grow the Roads
Cities, counties, states, and even the federal government spend millions of dollars a year, maybe billions in total, to maintain the roads. In the freeze-thaw zone, it is even worse than places like Arizona or Georgia. Now, road repair and reconstruction provides jobs for a number of people, but could there be a better way?
Engineering firms have tried everything that can be done materially and mechanically. If someone really wants to solve this problem, it is time to turn to a new frontier: genetic engineering. It is time to grow the roads instead of repairing them. This problem breaks down into a number of sub-problems:
Surface: The surface of this genetically engineered (GE) roadway would have to provide a high-coefficient of friction in all conditions. The surface has to be relatively hard and tough, as is the case with present road materials. But it cannot be too brittle, either. It also has to be rapidly self-healing. Perhaps some sort of material resembling bone, crustacean shell, or tree bark might be used as the basis for growing this material.
Anchorage: The roadway has to be connected to the earth beneath. We cannot have it coming loose, or peeling off like the skin on a blister, when a truck starts skidding. This GE road might use deep roots of cacti or trees that are native to areas of high winds for anchorage.
Striping: Stripes for lanes and the edges of the road could be applied as they are now, by painting them. Perhaps it would be necessary to develop new forms of paint. Perhaps it would be possible to apply a substance that would bring about a natural color change, just as temperature changes can spur color changes in the coats of certain animals.
Restriction of Growth: Once this growing roadway is out in the world, how do we keep it from paving the planet? There would have to be a way to restrict growth. Perhaps the creators of this new species could engineer in an affinity for present road-building materials. Maybe it would only eat concrete and asphalt? Maybe it would have to be fed a limited amount of some special substance to grow, as was supposedly true in Michael Chrichtonís Jurassic Park. Maintenance companies could dump the substance out of salt trucks. Too much traffic? Need to expand from two lanes to four? Get out the salt trucks!
Propagation: If the road is a living thing, propagation will probably not be a problem. On the other hand, if the genetic engineering firm wants to make money from this new product, they will need to ensure that they have control of growing these new roads.
Bridges: Bridges might present a different problem, since they do not pass directly over the ground. If the anchorage used is a root system, what does it attach to on a bridge? So, perhaps bridges would be created and paved in the same way as they have been all along. Or maybe they would also be grown, either using the same organism or another genetically engineered organism.
Seasonal Adjustment: These roads could be engineered to create seasonal advantages. Maybe they would shunt off heat in the summer or warm themselves in winter, melting ice and snow. They could eliminate the freeze-thaw cycle. They could absorb moisture so the road wonít be slick.
If such a road plant or animal can be engineered in the near future and the problems worked out, it would be a boon to humanity and government budget constraints for as long as we use ground-based transportation.
This was originally posted as a blog on 13 APR 2004 on another site.
Update on 21 JUN 2016: A similar idea is now being implemented: Self-Healing Concrete.
Site last modified: 26 JUN 2016