When do campaign signs go up for US Presidential Elections?

I am planning a six-month road trip throughout the USA, and I have a pretty broad timeline for when it could start, but I’m hoping to go sometime within the next couple years. I want to film the drive with a dash cam, and make a video/website/art project from the footage. Just today it occurred to me that there is an election in the states next year, and that the roadsides being full of trump/democrat signs would really deteriorate the quality of that project.

So when do signs usually go up? How many are there, particularly on long interstate highways?

[ Politics ] Open Question : Bernie Sanders broke the record for most donations for a presidential campaign in 24 hours, do you think he can win the presidency?

Bernie Sanders broke a U.S. record of 6 million dollars raised in 24 hours from small public donations. Do you think he can win the presidency with this booming support he has right out of the gate?

[ Civic Participation ] Open Question : Among the prospective 2020 presidential candidates I’ve listed, who are you most likely to support and which ones would you approve of?

Joe Biden Michael Bloomberg Richard Blumenthal Cory Booker Sherrod Brown Steve Bullock Peter Buttigieg Julian Castro Mark Cuban Andrew Cuomo John Delaney Jeff Flake Tulsi Gabbard Eric Garcetti Kirsten Gillibrand Kamala Harris John Hickenlooper Eric Holder Jay Inslee Dwayne Johnson Tim Kaine John Kasich Joseph P. Kennedy III Amy Klobuchar Mitch Landrieu Terry McAuliffe Jeff Merkley Seth Moulton Richard Ojeda Martin O’Malley Beto O’Rourke Deval Patrick Tim Ryan Sheryl Sandberg Bernie Sanders Howard Schultz Tom Steyer Eric Swalwell Donald Trump Mark Warner Elizabeth Warren Mark Zuckerberg