What development caused a decline in the use of railroads?

At the beginning of the last century railroads were used to haul everything. Powerful railroad barons made fortunes without having to be accountable to the public or considerate to customers. But cars and trucks changed all of that. And by 1970, the rail industry was beset with problems. Trucks were taking all the new business. And even so the rail industry remained indifferent to customers. Also many regulations kept the rail industry from adjusting to shifting markets. But in 1980, the rail industry entered the modem era when a deregulation bill was passed that allowed railroad companies to make quick adjustments to fees and practices. Companies reduced their lines by 1/3 and used fewer employees. They also took steps to minimize damage to products. And to increase their shipping capacity by stacking freight containers on railroad cars. To accommodate these taller loads, underpasses and tunnels were enlarged. The image of the rail industry has changed dramatically. Today companies are very responsive to customers and are gaining increasing market shares in the shipping industry. The railroad safety record is also strong. Freight trains have an accident rate that is only 1/3 that of the trucking industry. Trains also come out ahead of the trucks on environmental grounds because they give off only 1/10 to 1/3 the pollution that is emitted by trucks. And railroading does not wear out highways as trucks do.