Overview
Lap times data (laptimes.json) provides comprehensive timing and performance information for each completed lap, including sector times, speed trap measurements, tire information, and data quality indicators.
| Field | Full Name | Description | Unit | Notes |
|---|
| time | Lap Time | The actual lap time for this lap | seconds | |
| lap | Lap Number | Which lap this is (1st, 2nd, 3rd, etc.) | Integer | Counts from 1 |
| sesT | Session Time | When this lap ended relative to session start | seconds | |
| lST | Lap Start Time | When this lap started relative to session start | seconds | Lap ended at “sesT”, started at “lST” |
| lSD | Lap Start Date | Calendar date/timestamp when lap started | Date string | Useful for multi-day sessions |
Sector Times
The track is divided into 3 sectors. Sector times help identify where a driver gained or lost time.
| Field | Full Name | Description | Unit |
|---|
| s1 | Sector 1 Time | Time to complete first section of track | seconds |
| s2 | Sector 2 Time | Time to complete second section of track | seconds |
| s3 | Sector 3 Time | Time to complete final section of track | seconds |
| s1T | Sector 1 Session Time | Session time when the Sector 1 time was set relative to session start | seconds |
| s2T | Sector 2 Session Time | Session time when the Sector 2 time was set relative to session start | seconds |
| s3T | Sector 3 Session Time | Session time when the Sector 3 time was set relative to session start | seconds |
The sum of s1 + s2 + s3 equals the total lap time. Session time fields (s1T, s2T, s3T) indicate when each sector was completed during the session.
Speed Trap Data
Modern F1 tracks have speed guns that measure top speed at specific locations.
| Field | Full Name | Description | Unit |
|---|
| vi1 | Speed @ Intermediate Point 1 | Top speed measured at speed trap in Sector 1 | km/h |
| vi2 | Speed @ Intermediate Point 2 | Top speed measured at speed trap in Sector 2 | km/h |
| vfl | Speed @ Finish Line | Top speed measured at the finish line | km/h |
| vst | Speed @ Longest Straight | Top speed measured on the longest straight | km/h |
| Field | Full Name | Description | Type | Values |
|---|
| compound | Tire Compound | The type of tire being used | String | ”SOFT”, “MEDIUM”, “HARD”, “INTERMEDIATE”, “WET”, “UNKNOWN” |
| life | Tire Life | Laps driven on this tire (includes laps in other sessions for used sets of tires) | Integer (laps) | |
| fresh | Fresh Tire | Was this a new (fresh) tire when fitted? | Boolean | True = new tire, False = used tire. Tire had TyreLife=0 at stint start |
| stint | Stint Number | How many pit stops has this driver made | Integer | First stint = 1, after 1st pit stop = 2, etc. |
Tire life includes all laps on that tire set, even from previous sessions. A tire with life=5 in qualifying may have been used in practice sessions.
Position and Status
| Field | Full Name | Description | Type | Notes |
|---|
| pos | Position | Driver’s position in the race/sprint at the end of this lap | Integer: 1-22 | ”None” for FP1, FP2, FP3, Sprint Shootout, and Qualifying, as well as for crash laps |
| status | Track Status | A string that contains track status numbers for all track status that occurred during this lap | String | Examples: “1”, “216” (multiple statuses) |
| pb | Personal Best | Indicates whether this lap is the official personal best lap of a driver | Boolean | If any lap is quicker than their PB, the quicker lap is invalid (e.g., track limits exceeded) |
If a driver pitted during this lap, it was either an in-lap (driving into pits) or out-lap (driving out of pits).
| Field | Full Name | Description | Unit | Notes |
|---|
| pin | Pit In Time | When the driver entered the pit lane relative to session start | seconds | ”None” if this wasn’t an in-lap |
| pout | Pit Out Time | When the driver exited the pit lane relative to session start | seconds | ”None” if this wasn’t an out-lap |
Data Quality and Accuracy
| Field | Full Name | Description | Type | Notes |
|---|
| iacc | Is Accurate | Is this lap timing data considered accurate? | Boolean | Indicates lap start and end time are synced correctly. Lap time and sector times are always considered accurate if they exist. Laps marked as inaccurate need to be handled with caution |
| ff1G | FastF1 Generated | Indicates that this lap was added by FastF1 | Boolean | True means some missing data was filled in. Such laps have very limited information available and data is partly interpolated or based on reasonable assumptions |
| del | Deleted | Indicates that a lap was deleted by the stewards | Boolean | For example, because of a track limits violation |
| delR | Deleted Reason | Gives the reason for a lap time deletion | String | |
Laps with iacc=False should be handled with caution as they may contain timing errors that are not easily spotted. They have failed basic accuracy checks.
Laps with ff1G=True are partial reconstructions. Common cases include adding a partial last lap for drivers who retired on track.
Driver/Team Reference
| Field | Full Name | Description | Type | Example |
|---|
| drv | Driver | Driver identifier/code | String | ”LEC” |
| dNum | Driver Number | Car number for cross-referencing | String | ”16” |
| team | Team | Team name | String | ”Ferrari” |
See Also
