Technology companies and automakers are revving up their respective self-driving technologies in a race to have autonomous cars on the road by 2020, with Tesla even attempting to undercut the competition and deliver one in 2018.

But even when the technology is ready, getting the autonomous vehicles on the road will be a lofty challenge in itself, thanks to federal regulations. The National Highway Traffic Safety Administration (NHTSA) mapped out some of these issues and roadblocks that could delay the debut of autonomous vehicles on public roads as part of its massive 136-page March preliminary report. Yes, a 136-page preliminary report.

The overwhelming point? That it could be well past 2020 when autonomous vehicles, and those making them, pass an uphill climb of federal regulations that lie ahead.

"Current Federal Motor Vehicle Safety Standards (FMVSS) do not explicitly address automated vehicle technology and often assume the presence of a human driver. As a result, existing language may create certification challenges for manufacturers of automated vehicles that choose to pursue certain vehicle concepts," the first of many statements in the NHTSA's Executive Summary reads.

Although automakers can apply for rule exemptions, they're not guaranteed to get them, as the NHTSA can decide on a case-by-case basis, spelling out many of the issues it already has in this report, including just about every facet of the autonomous cars and their overall driving.

The good news is just last month, the NHTSA ruled that the artificial intelligence system steering Google's autonomous car could be considered a driver under federal law. However, the same agency could take issue with the company's vehicles not having pedals or a steering wheel, so stay tuned.

Perhaps, Google and auto execs also in autonomous vehicle development could help ease the NHTSA's minds Tuesday, when they meet before Congress to discuss steps being taken to develop safer and effective self-driving cars.

In particular, Chris Urmson, the director of Google's Self-Driving Car Project, is slated to testify before Senator John Thune, who chairs the Senate Commerce Committee. Auto execs from General Motors, Delphi Automotive PLC and Lyft will also be present to speak about advancements in autonomous vehicle technology and how they could aid Americans.