For years, Typodermic has offered a or strictly Free for Personal Use model for older fonts like Roadhouse. You can legally download the font without paying a cent if:

To get the official Oblique variant specifically: You may need to purchase the full family from Typodermic or MyFonts, where the oblique is included as a separate style.

If the deal looks too good to be true (e.g., "Full commercial license for $0"), it is a trap. Legitimate foundries do not give away $49 fonts for free.