Summary
A study published by Johanna.be says Tesla FSD (Supervised) exceeded the 30 km/h limit in 55% of tested Brussels segments. It also reports incorrect speed-limit displays and rule violations in other low-speed settings.
A study published by Belgian nonprofit Johanna.be on 24 September 2026 reports that Tesla’s FSD (Supervised) exceeded the legal speed limit in 55% of the tested 30 km/h segments in the Brussels-Capital Region. In those segments, the study says, the average achieved trajectory speed was 44 km/h.
The results concern tested locations, not every trip made using the system. Johanna.be’s summary does not give the number of segments or describe the test protocol, so the reported percentages cannot be read as estimates of how often the system would break rules across all journeys.
Findings in low-speed areas
Johanna.be says the system displayed an incorrect speed limit to the supervising driver in the large majority of the tested 30 km/h zones. In many instances, the vehicle recognised a 30 km/h limit but then displayed 50 km/h to the driver. The group says this could mislead drivers and contribute to the system’s speeding.
Additional tests in residential living areas found that FSD exceeded Belgium’s 20 km/h limit at 42% of the locations examined, according to the study. In bicycle streets, the group reports that the system repeatedly tried to overtake cyclists, despite Belgian traffic rules prohibiting the manoeuvre.
The findings were not uniformly negative. Johanna.be says FSD generally behaved cautiously and courteously around pedestrians and cyclists during the test programme, often yielding appropriately. Its conclusion is that these behaviours do not make up for the reported speeding and failure to follow key traffic rules.
Report sent to authorities before planned vote
Johanna.be says it sent the report on 7 September 2026 to the Dutch vehicle authority RDW, which it identifies as having granted preliminary European type approval for Tesla FSD (Supervised), and to the Flemish ministry responsible for admitting the system in Belgium. The group asked the authorities to reassess the approvals in light of its findings.
The nonprofit says it published the report so stakeholders could consider it ahead of a vote on European approval for FSD, then scheduled for 6 October 2026. The reported findings raise questions about how the system handles local speed limits and rules designed for streets shared with cyclists and pedestrians; the study summary does not provide the test counts or conditions needed to judge how broadly its results apply.