Duke787

Both very good museums.

I live here (in Durham and have for the vast majority of my life) and was the one who mentioned traffic.

I-40, the main highway to the airport from both Raleigh and Durham has gotten increasingly busy over the last few years and the area by the airport is especially bad (typically worse going towards Raleigh in the PM but can be bad in both directions).

I would start checking around 4pm. It won't necessarily take over an hour but it's certainly possible.

I definitely wouldn't leave later than 1700 but would be prepared to leave around 1630 if things are already skewing toward heavy traffic.

With no traffic it should only about 20-25 minutes and my assumption above is weekday travel, if weekend travel leaving at 5pm should be perfectly fine.