Ride-sharing company Uber has shut down one of its more ambitious research projects, a self-driving truck program.

It seems that Uber’s attempt to revolutionize the future of truck driving has failed as the company has closed its self-driving truck project, TechCrunch reports. The company will be moving employees working on the self-driving truck program to its autonomous car division, Uber also stated that its on-demand logistics side-project Uber Freight will remain unaffected by this decision.

Eric Meyhofer, the head of Uber Advanced Technologies Group, said in a statement: “We’ve decided to stop development on our self-driving truck program and move forward exclusively with cars. We recently took the important step of returning to public roads in Pittsburgh, and as we look to continue that momentum, we believe having our entire team’s energy and expertise focused on this effort is the best path forward.”

Uber’s foray into the world of self-driving delivery trucks was a result of their controversial acquisition of self-driving truck startup Otto in 2016. The acquisition caused some trouble for Uber after Google parent-company Alphabet claimed that Otto was a shell company meant to deliver stolen technology by former Google engineer Anthony Levandowski who had worked on Google’s own self-driving car project, Waymo. The two companies eventually reached a settlement in which Uber paid Waymo $245 million worth of Uber’s private shares at the companies 2015 valuation.

Uber seemed to be in the clear to push forward with their self-driving truck project but the company received a round of bad PR in March when a self-driving Uber vehicle hit and killed a 49-year-old woman in Arizona. The company immediately ceased self-driving car tests as federal investigators looked into the accident. Subsequently, the company was forced to lay off hundreds of safety drivers in Arizona and Pittsburgh and has only recently begun taking steps to relaunch its self-driving car program