Interesting discussion.
Here's an interesting article on the contention between freight trains and passenger rail:
Wear and Tear. Freight trains loaded with cargo are extremely heavy--many times heavier than passenger trains--and they rumble along much more slowly than passenger trains. These heavy freight trains are extremely hard on the tracks, causing much wear and tear. Because heavy freight trains move slowly compared to passenger trains and cargo doesn't complain when subject to a rickety ride, freight companies can get by on poor-quality track. They have little incentive to maintain the quality of the tracks to the level that good passenger service requires. It's unsafe for passenger trains to travel at high-speed on poor-quality track, so passenger trains have to slow down in places where track has only been maintained only to levels acceptable for freight.
Underinvestment and a vulnerable system. Unlike the interstate highway or federal aviation systems, the United States has invested comparatively little in our national rail infrastructure. Freight railroad companies haven't enjoyed the subsidies of their counterparts in the trucking or aviation industries. This results not only in poor-quality railroad tracks that aren't well-maintained, but also, many miles of single track, which in the automotive world is equivalent to having a narrow single-lane country road instead of a two-lane highway. Continuing the analogy, if a vehicle on a single-lane road breaks down, all traffic on the road comes to a halt, unable to proceed until the blockage is removed. Freight companies generally have not invested in preventative maintenance and have thousands of miles of track to maintain, as well as lots of ancient equipment (such as control signals) that's prone to failure. When something breaks, it can take them several hours to get to the site of the failure and fix it. If it happens to break along a single-track section, it can prevent a passenger train from proceeding for many hours.
When it comes to making money, passengers come last. The freight railroad companies' main goal is to make a profit. Unlike in Switzerland, freight shipments in this country often run on an erratic schedule. Due to poor infrastructure and extremely heavy congestion on some routes, freight trains are liable to show up at unpredictable times. Union Pacific has been known to hold up a passenger train to allow a long, slow freight train that is behind schedule to proceed ahead on a single track. Remember that UPRR makes a lot more money from the freight train than from the passenger train -- although some passenger agencies have worked out financial incentives to UPRR to allow passenger trains to proceed on schedule.
An overloaded system. Problems with congestion and delays have increased considerably on some routes, because the volume of goods that our country imports from places like China has increased some 10-fold in the past several years. The more freight that needs to be hauled from our western ports, the more all the above problems are exacerbated.
Public has little leverage. Freight railroad companies are nearly as old as our country and its westward expansion, and early on these companies gained special legal status and rights. For example, public entities cannot exercise powers of eminent domain on the freight railroads to gain use of their property, even if it's for the public good. Public entities have very little leverage over the freight railroad companies, and must generally agree to pay very large sums of money to fix up or build new tracks on railroad property in exchange for permission to run additional service on tracks owned by the railroad. This hinders the ability of a passenger rail agency to improve the quality and frequency of service on tracks owned by freight railroads.
Federal and state regulations. When passenger trains share tracks with freight trains, additional federal and state regulations apply to the design of the trains and stations that make it difficult to improve the quality of the service.
Here's another interesting factoid:
"One 80,000 pound truck may do as much wear-and-tear damage to roads and bridges as do 9,600 passenger cars."
