Imola is one of only a handful of grand-prix-grade circuits in the world that runs anti-clockwise. The convention of clockwise racing emerged from horse-track tradition; Imola's reversed direction means its drivers spend the lap turning predominantly right, an unusual physical load on the neck. The track snakes through wooded hillside on the bank of the Santerno river, with significant elevation changes between the start–finish straight at the lowest point and the back section through Acque Minerali and Variante Alta at the highest.
Construction began in 1950 on a piece of municipal land near the town of Imola. The first race was held in 1953 — a 5.000 km road course without chicanes, used initially for sports cars and motorcycle competition. Enzo Ferrari attended often and the track quickly became a Ferrari proving ground; the layout was raced as the Coppa Shell and the 1000 km of Imola endurance event. The first F1 cars to lap Imola appeared in non-championship form, but it was not until 1980 that the circuit hosted a World Championship round — and even then, only because Monza was being resurfaced.
After Monza returned to favour, Imola needed an identity. The neighbouring micro-state of San Marino — too small to support a circuit of its own — agreed to lend its name, and from 1981 onward the race was contested as the San Marino Grand Prix. Twenty-six San Marino GPs were held at Imola over the next quarter-century, often as the season's European opener, and the race became a fixture of springtime motorsport in northern Italy.
Notable San Marino Grands Prix include the 1982 race — boycotted by all FOCA teams in a political dispute, contested by only fourteen cars, and decided by a controversial team-orders dispute between Didier Pironi and Gilles Villeneuve that left Villeneuve furious; he died two weeks later at Zolder. The 1989 race saw Gerhard Berger crash heavily at Tamburello when the front wing failed; his Ferrari caught fire and rescue workers extracted him in seconds, an outcome that flattered the corner's run-off and left the safety-of-Tamburello question publicly unaddressed.
The 1994 San Marino Grand Prix is the most-cited safety inflection point in the modern history of motorsport.
Friday practice: Rubens Barrichello crashed his Jordan at Variante Bassa, struck the kerb and was launched into the catch-fencing, missing serious injury by the smallest margins.
Saturday qualifying: Roland Ratzenberger, a 33-year-old Austrian making only his third F1 start, crashed his Simtek at the Villeneuve corner after a front-wing failure, hit the concrete wall at undiminished speed and was killed instantly. He was the first F1 driver fatality at a Grand Prix weekend in twelve years, since Riccardo Paletti at Montréal in 1982.
Sunday race: On lap 7, Senna, leading in the Williams FW16, ran wide at Tamburello — long the circuit's most-feared corner — and struck the concrete wall on the outside at almost 220 km/h. A piece of suspension penetrated his helmet; he was airlifted to Maggiore Hospital in Bologna and pronounced dead later that afternoon.
The fortnight after the accident saw the most extensive safety review F1 had ever undertaken. Tamburello, Villeneuve and Variante Bassa were torn up over the close-season; the GPDA (Grand Prix Drivers' Association) was re-formed; cockpit head-protection, mandatory crash-tests and circuit run-off review programmes were introduced. Imola itself was transformed — Tamburello and Villeneuve became chicane sequences, Variante Bassa was modified, and the speed of the lap dropped by ten percent.
The 1995 reconfiguration converted Tamburello from a flat-out left-hander into a low-speed left-right chicane and added a similar chicane at Villeneuve. Variante Bassa was reprofiled. The chicanes were unloved by drivers — they broke the rhythm of what had been a flowing, characterful track — but they shed the corner-speed that had made the accidents so violent. The reconfigured circuit continued to host the San Marino GP through to 2006, when it was dropped from the calendar in a calendar-rationalisation that also removed Magny-Cours.
Without F1, Imola became a regional motorsport venue. The track hosted the World Touring Car Championship, Superbike World Championship and various national series, but lost much of its international profile. A FIA Grade-1 homologation renewal in 2014 paved the way for a possible return, and substantial pit-complex work was carried out in anticipation, but no calendar slot opened.
The 2020 COVID-19 pandemic forced F1 to reorganise its calendar at short notice, and Imola — long-prepared and FIA-ready — was added back as the Emilia Romagna Grand Prix. The race has been held annually since (with the 2023 edition cancelled due to severe flooding in the region), and the circuit has retained its 1995-era layout with only minor tweaks to kerbs and runoff. Track limits are aggressively policed at Variante Alta and Acque Minerali, where modern asphalt run-off invites drivers to widen the line beyond the white painted boundary.
Counter-clockwise from the pit straight, the modern lap is:
Tamburello — the 1995 chicane, a hard left-right after the start-finish straight. The original 1953–1994 Tamburello was a long, fast left-hander.
Villeneuve — another 1995 chicane, named for Gilles Villeneuve, where Ratzenberger died.
Tosa — a tight left-hander, traditional overtaking spot, named for the local town.
Piratella — a fast left over a crest, blind on entry; the corner where the back-section character begins.
Acque Minerali — a tricky double-right downhill sequence, named for a mineral-water spring on the property.
Variante Alta — a high-speed chicane at the highest point of the circuit.
Rivazza — two left-handers descending back toward the river plain, named for the local district.
Variante Bassa — the final chicane onto the pit straight, modified post-1994 and again post-2020.
Imola is in every major car sim. Assetto Corsa Kunos has the 2018 layout; AMS2 also has the 2018 layout plus a historic 1972 mod. ACC ships the 2020 layout in the Intercontinental DLC. iRacing has the modern circuit. LMU has it as a WEC venue.
This base circuit has multiple variants in our database, spanning the original 1953 sports-car layout, the 1980-1994 chicane-free F1 era, the post-1994 chicane reconfiguration, and the present-day Emilia Romagna GP configuration.