Pros
If you have a passion for public service, you can achieve a lot at Caltrans. As a State agency, they have a lot of say in what happens. Co-workers are great people. Like any workplace, there are bad apples, but those dedicated to serving the public are some of the best co-workers you'll ever have. Honestly, it's my coworkers that I miss the most. Opportunity for upward mobility is high. Caltrans is currently experiencing the "Silver Tsunami," so there is a lot of turnover up top. Benefits are excellent. Pension, great healthcare, EAP, generous time off, flexible work schedule (not sure what post-COVID teleworking will look like, but a 9/80 was available and flexible hours centered around the availability to make meetings was the options when I was there).
Cons
Pay is low, especially when starting out. The old school view of DOT's as Highway Departments is still pervasive. However, it is indeed shifting. But a lot of new people with new views on that end are coming into Caltrans. To do your job well, you have to be willing to do a lot of extra leg work and make up for people more interested in just collecting their benefits. But, they won't stop you if you want to do the job well.