Creating a ho track atlas 100 code

[Wrex343]

You need to make some basic decisions about the era ( time) you want to model, model a real road area or make up a fictious railroad. What features do you want like industries, mountains, lakes, residential or farm areas or wilderness.? What is your budget for pre-assembled structures, rolling stock and accessories? What are your skills for painting and building benchwork or models?
How ambitious are yu to build your railroad in sections or tackle a large layout?
Much will depend on the house you get for space and available configuration.
Make a list of the things you gotta have, the things you wanta have soon and things that would be nice to have. Write your list in pencil and have a big eraser handy,
Buy ONLY things that are on your gotta have list until later.
Good luck. Remember: this advice is worth exactly what you paid for it!

90s to present

 

[Iron Horseman]

So question 90s to present day locos

So at the beginning of the 1990s on the EMD side the SD-4x series and GP-38s and GP-40s still ruled the rails. While the GE camp had their -8s.
by the mid 1990s the horse power wars started when EMD came out with the SD-70 and GE matched with the Dash 9s. The SD40s and GP40s disappeared from the mainlines seemed like it was overnight. Side story was that in 1993 GE in started the AC locomotives controlling them with frequency rather than variable DC voltage. By the end of the 1990s AC and high adhesion trucks became the norm. Railroads like the BNSF and UP replaced older locomotives by the thousands. So by 2010 there was zero similarity to mainline locos as there had been in 1990.

Caterpillar (Progressive Rail) SD70eAC variants and GE GEVOpowered FLX drive ET44ACs are the current offerings. However because of cost many of the older 2000s locomotives are being refitted with new prime movers and electronics, so who knows what they will end up looking like. Probably have vents and ports and blowers changed all over the place.