"Crayoning" is a derogatory term in transit and urban planning circles for overly-optimisic or unrealistic ideas of where to put rail or transit lines, or development in general. The term derives from the idea of drawing lines on a map with crayons, which is an overly crude way to design the routes of either local or long distance trains.
Some background on how crayoning, and the derision of it, became a thing: compared to most developed nations, the United States has much weaker rail transit, and is much more automobile (and thus, fossil fuel dependent). The reasons for this are manifold, some of them having to do with social trends (white flight and suburbanization post-World War II), while some of them are due to the physical geography of the United States (The Netherlands, often the darling of transit advocates, has a population density greater than the most densely populated US state, and has a high point of about 1000 feet). But many transit advocates want the United States to somehow circumvent widely different historical, demographic and geographical realities, and the way to do that is: putting a big mark across a map, and don't ask "how" or "why".
For example, California and the Pacific Northwest are both population centers and "high tech", so it makes sense to have a high speed rail line between them! Draw a line on a map between Sacramento and Eugene! The problem is, in reality, there is 400 miles between these cities, and the current rail line crosses the Cascade Mountains twice. And the largest population center between them on that line is Klamath Falls, Oregon, a town of about 25,000 people. Considering the cost and time spent trying to get California High Speed Rail finished on the flat terrain between major population centers, the idea of High Speed Rail between California and the Pacific Northwest seems like a matter of whimsy.
A lot of more far-fetched transit ideas are good as aspirational goals. With enough time, money, and technological improvement, it might be possible to do some of these projects. The biggest problem with crayoning is that it can block achievable improvements from being made right now. After all, who wants to talk about things like fixing water fountains and bathrooms, having better real time scheduling information, having shuttle buses to rail stations, or a dozen other small improvements, when we can wait for a 500 mph maglev?