I regret not packing 3 items on a road trip. Together, they would've cost less than $75 and made living in a campervan easier.

Side-by-side images of the author and her rental van.Monica Humphries/Business Insider

• Last October, I took a 3,000-mile road trip in a campervan.
• While I remembered to pack important things like a phone mount for driving, I did forget key items.

As I packed up my campervan — aka the place I would call home for two weeks — I crossed my fingers and hoped I had everything I'd need.

I was embarking on a two-week van trip spanning 3,000 miles. I planned to pass through six states, meaning I'd also hit a range of weather and temperatures ranging from the chilly mountains of Colorado to the California desert.

While I had numerous bags, suitcases, and backpacks packed full of items to meet those needs, I was confident there was something I was bound to forget.

By the end of the trip, I realized I had almost everything I needed — emphasis on almost.

While I was thrilled I remembered to pack a phone mount for long drives, I regretted leaving a few things off my packing list.

Here's what I won't forget if I embark on another cross-country road trip.