While it is theoretically possible to use overhead electric lines to power vehicles on highways, there are a few challenges that would need to be overcome in order to make this a practical solution. For one, the infrastructure required to support such a system would be quite extensive, and would likely be expensive to install and maintain. Furthermore, the system would only be able to provide power to vehicles while they are on the highway, so they would still need some form of on-board power source for use when they are off the road. Overall, while this idea has some potential, there are currently more practical and cost-effective solutions for reducing the weight of vehicles, such as the use of lightweight materials and more efficient batteries.