We investigated single word reading in a context where isolated word presentation is not unusual-reading road signs in a simulated car driving situation. Participants had to indicate if the inscription on the road sign was a real word or not (lexical decision). The critical nonwords were created in two ways: by transposing two letters in a real word (e.g., the word "Highway" becomes "Hihgway") or by substituting the same two letters with different letters ("Hifpway"). The baseword used to create the critical nonword stimuli were either congruent with a driving context (e.g., "highway") or incongruent (e.g., "garden"). Nonwords created by a letter transposition were harder to reject as such compared with letter substitution nonwords-a transposed-letter effect. The effect of baseword congruency was not significant and did not interact with the transposed-letter effect.