Traffic on the Brazilian highway BR-364 was backing up for miles after drivers discovered the unusual animal blocking the road.
An enormous, 3-metre long snake was found lying across the road near the city of Porto Velho in the country's north west.
Concerned drivers stopped their vehicles to help the giant reptile across the road.
Crossing the multi lane highway, the unusual animal was escorted across the road with some bystanders slowing oncoming vehicles and others just stopping to video the spectacle.
Though few drivers dared get closer than a couple of metres.
"There are no signs for the cars to wait so she can cross," driver Italo Nascimento Fernandes told wildlife website The Dodo. "I have seen snakes run over on the highway before, and think such thing is a crime."
The giant snake was documented slithering across the road in multiple facebook videos.
Eventually it crossed the road partition and made it safely to the other side.
The 30kg snake was probably an Anaconda in search of food, biologist Flavio Terassani told local paper G1.Globo.
The animals have been appearing regularly in cities in search of small animals to prey on, said Terassani.
"They feed on rats, but in urban areas they have been known to feed on dogs and even cats."
These snakes can be found in many countries across inland South America.
However, the appeal of urban hunting grounds has lead to a number of giant snake spottings.
In 2013 an even larger Anaconda was discovered behind a tourist resort in Los Llanos, Colombia. Spotted by a french tourist, the 16-foot snake was removed and driven to a nearby lagoon.