Processing Speed
Lane Keeping Task
Also called: standard deviation of lateral position, SDLP, simulated lane keeping
Measure how steadily people keep a car in its lane on a winding road, with the weaving of the car (SDLP), mean lateral position and lane departures.
7-9 minTimed: desktop or laptop with a mouse or trackpad
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Try it here first, with no account.
- Papers, 2021 to 2025
- 94
- Evidence grade
- C
- Registered clinical studies
- 59
What it measures
Measures how steadily people keep a car in its lane. Participants steer a car along a winding road at a set speed while gusts of wind push it sideways. The main score is the standard deviation of lateral position, the weaving of the car.
Constructs
- Visuomotor control
- Sustained attention
- Lane keeping
Research uses
- Human factors research
- Driving simulation studies
- Within-study group comparison
How the paradigm works
The Lane Keeping Task measures how steadily people keep a car in its lane. The car runs at a constant 95 km/h along a winding two-lane road, and gusts of side wind push it sideways now and then. Participants steer with the arrow keys or, as a study setting, the mouse, and keep a steady position in the lane wherever they like. The main score is the standard deviation of lateral position (SDLP), the weaving of the car, as in the on-the-road driving test of O'Hanlon (1984) and its standard procedure (Verster and Roth, 2011), here as a drawn, simulated drive.
More about the paradigm
The standard session has a 45-second practice drive, then one continuous drive of 5 minutes; studies can set 2 to 20 minutes. The road's bends and the gusts are drawn from the session's seed, and the car's lateral position is saved five times a second. The drive pauses and blanks if the window loses focus. Desktop or laptop with a keyboard, or with a mouse for mouse steering.
Scores
- Weaving (SDLP)cm
- Standard deviation of the car's lateral position over the drive, from positions saved every 200 ms.
- Lower means steadier lane keeping
- Mean Lateral Positioncm
- Mean distance of the car's center from the center of its lane; positive is to the right.
- Describes where in the lane the car was kept
- Lane Departurescount
- Times the car's body crossed a line of its lane, from the saved positions.
- Lower means fewer departures
- Time Out of Lane%
- Share of saved positions with the car's body over a line of its lane.
- Lower means more time in the lane
- Weaving, First Halfcm
- SDLP over the first half of the drive.
- Compare with the second half
- Weaving, Second Halfcm
- SDLP over the second half of the drive.
- Higher than the first half means the weaving grew over the drive
- Pausescount
- Drive interruptions after focus loss, hiding the tab, resizing or the pointer leaving the page.
- Lower supports interpretation
- Long Frames%
- Share of animation frames longer than 50 ms.
- Above 0.05 is flagged
- Driven Timeseconds
- Drive time covered by the saved positions.
- Informational
- Planned Timeseconds
- Planned length of the drive.
- Informational
Use and evidence
94 papers from 2021 to 2025 name this task in their title or abstract, about the same as from 2016 to 2020. That ranks it 268 of 632 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 21 |
| 2024 | 15 |
| 2023 | 18 |
| 2022 | 19 |
| 2021 | 21 |
| 2020 | 22 |
| 2019 | 10 |
| 2018 | 27 |
| 2017 | 20 |
| 2016 | 15 |
| 2015 | 14 |
| 2014 | 22 |
| 2013 | 23 |
| 2012 | 11 |
| 2011 | 14 |
| 2010 | 13 |
| 2009 | 11 |
| 2008 | 4 |
| 2007 | 3 |
| 2006 | 8 |
| 2005 | 6 |
| 2004 | 7 |
| 2003 | 1 |
| 2002 | 3 |
| 2001 | 3 |
| 2000 | 2 |
Use grade D
30 to 99 papers from 2021 to 2025.
Evidence grade C
At least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies.
- Papers on test-retest reliability
- 0
- Papers on reliability or validity
- 25
- Registered clinical studies using it as an outcome
- 59
Measured on ConductCognition
Pooled across the studies that feed our platform norms, by device group. A figure needs 50 or more people.
No pooled figure yet.
Note on the counts: most counted studies use driving simulators or real cars, and most trial listings test medicines, alcohol or sleep loss.
How the grades work
Use: A is 1,000 or more papers from 2021 to 2025, B 300 to 999, C 100 to 299, D 30 to 99 and E fewer than 30. Evidence: A means at least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome; B, at least 8 test-retest papers, and either 5 registered clinical studies or 150 reliability or validity papers; C, at least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies; D, little published measurement evidence found. The counts measure use. They include every paper that names the task in its title or abstract. Grades describe the published research on this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.44.0, counted 12 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Road
- A drawn two-lane road at a constant 95 km/h, seen from behind the participant's car in the right lane, with gentle bends and gusts of side wind drawn from the session seed. No traffic.
- Drive
- One continuous drive of 5 minutes as standard, with 2 to 20 minutes available, after a 45-second practice drive with feedback.
- Steering
- Arrow keys as standard: a held key steers, and the steering returns when it is released. As a setting, the mouse: the pointer's distance left or right of the middle of the road sets the steering.
- Instruction
- Keep a steady position in the lane, wherever feels natural, as the standard procedure of the on-the-road test asks.
- Recording
- The car's lateral position every 200 ms, in cm from the center of its lane, with the road's bends and the gusts.
- Scores
- SDLP, mean lateral position, lane departures, time out of the lane, the SDLP of each half of the drive, and frame timing.
A simulated version of the on-the-road test: a drawn road, minutes rather than an hour, and keys or a mouse rather than a steering wheel. Scores describe lane keeping in this drive and do not measure fitness to drive or the effect of a medicine or alcohol on a person. Compare only drives of the same length and steering. No percentile output.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: the scored drive. A drive with no lateral positions invalidates; an unfinished drive, a car out of its lane more than half the time, three or more pauses and long frames are flagged. A drive without any steering is a missed response under the platform's timed-test rule.
Why these rules
Missed responses and responses under 100 ms keep the platform's timed-test rule: more than max(3, 25%) missed responses or more than max(2, 20%) responses under 100 ms invalidate, and any is flagged. A response under 100 ms cannot be a reaction to the stimulus. The weaving of the car is meaningful only when the participant steered: without steering, the wind and the bends alone move the car.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Drive length (minutes) | 5 | 2 to 20 |
| Steering | Arrow keys (standard) | Arrow keys (standard), Mouse |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Timed test: participants need a desktop or laptop with a mouse or trackpad. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- No percentile. Scores and quality flags only. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Participants completed the Lane Keeping Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; O'Hanlon, 1984), with the standard settings (drive length (minutes): 5; steering: Arrow keys). The main score was weaving (SDLP; standard deviation of the car's lateral position over the drive, from positions saved every 200 ms).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- O'Hanlon, J. F. (1984). Driving performance under the influence of drugs: rationale for, and application of, a new test. British Journal of Clinical Pharmacology, 18(S1), 121S-129S. https://doi.org/10.1111/j.1365-2125.1984.tb02590.xThe on-the-road driving test, from which the weaving measure comes.
- Verster, J. C., & Roth, T. (2011). Standard operation procedures for conducting the on-the-road driving test, and measurement of the standard deviation of lateral position (SDLP). International Journal of General Medicine, 4, 359-371. https://doi.org/10.2147/IJGM.S19639The standard procedure: a constant speed, a steady position the driver chooses, the lateral position sampled through the drive, and SDLP over the whole drive.
Source papers
- O'Hanlon, J. F. (1984). Driving performance under the influence of drugs: rationale for, and application of, a new test. British Journal of Clinical Pharmacology, 18(S1), 121S-129S.Paradigm source, Adults
Questions
How long does the Lane Keeping Task take?
About 7 to 9 minutes, as listed in the test library.
What device does a participant need?
Timed test: participants need a desktop or laptop with a mouse or trackpad. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Weaving (SDLP), Mean Lateral Position, Lane Departures, Time Out of Lane, Weaving, First Half, Weaving, Second Half, Pauses, Long Frames, Driven Time and Planned Time. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Lane Keeping Task used in research?
94 papers from 2021 to 2025 name it in their title or abstract, about the same as from 2016 to 2020. That ranks it 268 of 632 test families in the ConductCognition test census (use grade D). Source: ConductCognition test census 0.44.0, counted 12 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Lane Keeping Task have?
In the published research, 0 papers report its test-retest reliability and 59 registered clinical studies use it as an outcome (evidence grade C in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
Drive length (minutes) (2 to 20) and steering (Arrow keys (standard), Mouse). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. English is on every plan, and the other languages come with yearly plans. Have a native speaker read the machine-translated text before launch.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
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