Global Change Science the Negative

Global Change Science

The negative effects of road surfaces on local, regional, and national ecosystems is empirically evidenced and a large contributing factor to the increasingly large carbon footprint of developed nations (Switalski, et al. 2004). The use of primarily asphalt and tar-based paving techniques though providing an effective road surface is damaging not only in the retention of solar radiation which raises the internal temperature of the earth, but also in the associated chemical run off, and necessary disruption of existing vegetation and animal life (Forman, 1999). The impact of human manufacturing and agricultural business on the climate is seemingly an inevitability of civilization. However, there are areas of waste which can be limited or repurposed granted initially at an expense, but ultimately beneficial in the long-term not only for individual nations, but also for the global environment as well (Switalski, et al. 2004).

Road surfaces are composed primarily of tar and asphalt-based pavement. This static substance leaches harmful toxins such as heavy metals and polycyclic aromatic hydrocarbons into the soil and ground water not only as a result of asphalt's inherent chemical makeup but also as a result of the interaction with vehicles and their associated waste (Kosson, et al. 2002). Further, when road surfaces must be replaced approximately once every ten years, there are large tracts of road material which must either be reused or disposed of spreading the effects of such toxins further than road ways and surrounding areas but into landfills and playgrounds where it may potentially come in direct contact with community water tables or even children and family pets.

Using alternative paving materials, while still utilizing the highly inorganic and ecologically disruptive method of "paving" is counterproductive in that the inherent problems with road surface is as much its construction as its chemical composition (Reid, 2000). There is enough paved roadway in the United States alone to drive to the moon and back again. This incomprehensibly large space serves no other purpose than the conveyance of human beings and goods from one point to another (Reid, 2000). While transportation is vital to the successful continuation of human progress, the method by which that transportation is achieved is constrained only by efficacy and imagination.

Currently, there are technologies in development which will allow for the collection of heat energy from paved roads not only for the purposes of contributing to the national grid (through thermoelectric generation) but also for the purposes of preventing ice forming within the road beds during winter (Switalski, et al. 2004). Additionally, piezoelectric devices can convert the pressure of cars driving over the road surface directly into electricity. Finally there is also a great deal of research going into the use of alternate materials which can be used to minimize the negative effects of leaching and ecological disruption (Forman & Deblinger, 2000).

This research independently may aid in the attainment of energy efficiency and environmental protection goals. However, each of these projects is being conducted independent of each other. What this study proposes is a combination of existing and yet to be developed road surface technologies and construction techniques which would capitalize on the inherent energy transfer between both cars and the road surface, as well as the sun and the road surface. This in combination with a more effective and dynamic containment matrix may ultimately not only have a long-term positive impact on the environment but also on the immediate ecological systems surrounding the road surface. I propose to test heat sensor receptor panels utilizing both solar and pressure energy in combination with a reclaimed rubber pellet bed and in a natural vegetation matrix.

Introduction

The need for improved road surface and road construction is apparent not only in the sheer number of automobiles passing along those roads but also the extremely negative environmental effects of inorganic structures which cover an area roughly equivalent to the size of South Carolina (Forman & Alexander, 1998). Agriculture and manufacturing are necessary industries and currently the dependence on oil which is no longer abundant in North America makes disasters like the BP oil spill and the Exxon Valdez oil spill which devastate the ocean ecosystem and severely disrupt carbon cycling through marine ecosystems an inevitability. Though altering the construction and surface of the road is a somewhat indirect approach to addressing global change, the tangential effects of making even small changes in this huge system will have highly significant positive consequences in the pursuit of developing planetary homeostasis where human needs as well as environmental concerns are equally balanced .

The road surface and bed design itself will be divided into three discrete sections. The base layer which is typically ash or other waste material will instead be tightly packed reclaimed rubber pellets. These pellets will be held in place by hard rubber barriers laid along the length of the road. The use of reclaimed rubber in place of ash, slag, or broken concrete will allow for more effective drainage as well as allowing for the natural thawing and freezing cycles without resulting in the characteristic stress fractures in static materials such as concrete and asphalt. Further, rubber will allow for less negative effects of the leaching of harmful chemicals as well as the effect of natural vegetation forcing its way up through static asphalt.

The second layer will comprise of the various electrical conduits connecting each individual tile energy collection points along the length of the road surface. Though this will entail a disruption of the ecological system by building charge stations at intervals along road surfaces (ideally, fitted within existing highway service stations) the more environmentally friendly materials will ultimately work in concert with eco systems developing road works which actively work towards fuel independence as well as a healthier ecosystem. Waterproofing of the conduits and individual tiles will be necessary to ensure the integrity of the various electrical components. The conduits though more so than conducting collected heat and energy will also fix the tiles in place ensuring that when bearing the at times unevenly distributed load of vehicles they will not move or shift in unsafe manners.

The final component of this system is the actual road surface. This will be composed of solar and pressure heat collection tiles separated by a matrix of organic vegetation. Though vegetation in the road surface is extremely problematic in terms of traditional road surfaces, in the context of this new and innovative roadway solution it will provide a dual purpose. Using small sections of organic matter such as moss between the tiles will allow for carbon scrubbing from the exhaust of vehicles as well as allowing for more effective draining of the road surface as well as making it relatively impervious to freezing thawing cycles.

The entirety of this new road structure would be bounded on either side by hard rubber walls which would force the rubber pellets to remain tightly packed beneath the conduits. The use of rubber again as opposed to a more static substance again addresses the issue of a road surface needing to be able to shift, expand, and contract sometimes significant distances. In the heat of summer, bridges with a great deal of road surface have been known to expand as much as an entire kilometer in either direction. While this kind of shifting and expansion would be devastating to a static material, rubber would simply flex allowing the expansion without any perceptible change in the integrity or stability of the road itself.

The proposed new road structure would not only contribute to the national grid as well as furthering the realistic proliferation of truly electric cars, but it would also contribute to the national grid allowing the United States not only to reduce its carbon footprint but also reducing it's dependence on foreign oil. The global change implications of conversion of all U.S. roadway to roadway such as that proposed above are enormous.

In the United States and Canada people drive more than any other continent. North America as a continent also has more road surface than any other continent on earth. The carbon emissions alone from the United States motor vehicles are an estimated 268 grams per kilometer (Grimmond, 2007). That is higher than any other country in the world. Incorporating organic CO2 scrubbing materials into the road surface may greatly reduce the impact not only of individual vehicles but may also put the solar radiation which asphalt and tar absorb to better use.

The impact of road systems on the environment is larger simply than the contribution to the human carbon footprint. Road ways, and the methods by which they are constructed result in far reaching consequences for ecosystems both in the immediate vicinity of the roadway and even those tangentially connected via streams and food chains (Forman, 1999). In order to lay a road, land must be cleared of vegetation and wildlife. This disruption to the homeostatic balance of an environment affects all living organisms within that environment (Forman & Deblinger, 2000). More so than the land needed specifically for the road surface itself in order to provide access to construction vehicles and manual laborers additional space must be cleared resulting in further loss of vegetation and animal life. As the road is being laid the fumes from the chemical materials and the concussive force of the construction equipment are devastating to local wildlife (Forman & Alexander, 1998). The result, is displaced organisms which ultimately put increased pressure for food, land, and water on other ecosystems. The extent of these ripple effects are still yet to be fully known.

In instances where above or below ground water supplies must be altered in order to make way for a new road system the effects are if anything more dire. When laying the bed of a road, it is nearly impossible to prevent a percentage of the chemicals used in the road surface itself from leeching into the soil (Forman & Deblinger, 2000). When in the presence of water those toxins are carried the course of the water supply affecting all of the vegetation and wildlife which it comes into contact with. Further, small otherwise innocuous streams may become channelized as a result of road works. To channelize a stream indicates that its flow is concentrated and steered in more convenient directions (Switalski, et al. 2004). However the increased pressure of a higher volume of water results in increased erosion and may result in negative consequences for the local fish and amphibious population. The increased water flow may also concentrate any toxins or waste leaching into the water supply so that rather than relatively harmless levels of toxins may become more dire in terms of their impact on vegetation, wildlife, and even local human populations (Kosson, et al. 2002).

The materials proposed for this new system of road work and road surfacing are highly unorthodox. The use of reclaimed rubber, vegetation, and solar / pressure sensitive tiles is a combination which has not before been considered in road surfacing due to the perception that it would ultimately result in an unstable driving surface endangering the lives of motorists. It is my contention thought, that the tiles which would comprise the primary road surface and which would be anchored in place by a series of heavy duty conduits would provide at least as stable a driving surface as the one provided by asphalt. However, the fact that each tile would be independent allows for more dynamic movement and simpler repairs than are possible with a substance like asphalt. Potholes, cracked roads, unexpected or observed sinkholes would be actually impossible with this new proposed surface. Reclaimed rubber is effectively free of all of the most prominent drawbacks associated with asphalt and is unused because it is untested.

Project Description

The most effective proof of concept for this project would be an actual test of the proposed alternate road surface and energy collection system in laboratory simulated real world settings. As discussed above, threats to efficacy of road surface include; changes in external and internal temperature, moisture proliferation, stress, friction, compression, tension, torsion, and cutting. However, as the specific technologies necessary to implement the proposed road surface are still in development the most accurate way of conducting a proof of concept in the immediate future will be to develop a simulation utilizing data collected from real materials in the context of the full battery of testing which any proposed road surface would undergo prior to approval and implementation. The use of simulation data will ultimately not only be cost effective but also allow for the simultaneous running of multiple variations on the road surface thus proving time effective as well.

Testing physical samples in a laboratory at this point in the development process would be extremely costly and require not only a great deal of physical space but also a significant number of staff on hand 24/7 to monitor the progress of the experiment. Computer modeling allows not only for the simultaneous running of multiple conditions but the repetition of tests hundreds or even thousands of times assessing any and all possible outcomes of all possible scenarios. Researchers will be able to literally test the best and worst case scenarios in all possible conditions as well as assess the effects of normal wear and tear based on up-to-date traffic patter information from any place in the world.

The design of the study will be divided into two discrete phases which may require the inclusion of researchers with differing fields of expertise. This project will ultimately be an interdisciplinary study between environmental science, electrical engineering, civil engineering, and biology. The initial and perhaps most significant phase of testing will be the selection of raw materials, as well as the machining and construction processes for the individual components. Though rubber is the most heavily used proposed material the various requirements of the substance all of which must be controlled for in the reclamation of the pellets must be assessed in terms of realistic data based on the normal wear and tear of road surfaces. Data regarding the tension, torsion, pressure, heat, tearing, freezing, and innumerable other factors all of which are accessible data points must be compared to different chemical compositions of rubber in order to find which type is the most compatible with the specific requirements of a road bed.

The tiles will likely be made of some form of Piezoelectric substance embedded with solar collection panels. The material will have to be both abrasive and durable in order to successfully serve the purposes of road surfacing however it will also have to be sensitive enough to collect solar radiation and accurately measure the force applied by car tires. Though this challenge seems insurmountable as with the specific data points regarding the forces applied to a road bed the same data is available for road surfaces. It is simply a matter of comparing the data points which are available from the manufacturers of potential tile substances. One of the most important requirements of the tiles though is that they be extremely energy efficient. The purpose of this new proposed road bed and surface is to decrease the carbon footprint as well as removing as much of the burden from the environment immediately surrounding and tangentially connected to the road surface as possible. The specific electrical and mechanical components will need to be made wholly water proof in order for them to be able to withstand natural weather cycles. They will also need to be resistant to extremely high temperatures in the event of car fires which burn with enough heat to actually melt the surface of existing road structures. One potential upside to the use of heat and pressure sensitive tiles is that while car fires are devastating, the heat generated by one rather than being expended fruitlessly may be able to contribute effectively to the generation of electrical energy for the purposes of powering vehicles or contributing to national and local grids.