This study aims to evaluate effects of text layout on dual-task performance. The primary task was a simulated driving test. Independent variables in this study were line width and line spacing. While subjects "drove" in the simulator, they read English texts displayed with varied line spacing or line width. Subjects were twenty Purdue University students who are non-native English speaker. English was their second language. During the test, subjects' driving performance, eye movement and their text layout preference were recorded to analysis propose. The results indicated that changes in line width didn't impact driving performance, and changes in line spacing had a minimal influence on driving performance. Both line width and line spacing influenced reading eye movement measurements but did not influence the reading comprehension. Full-screen line width resulted in better reading performance than half-screen line width, but the subjects' line width preferences were not significant. Double-line spacing resulted in better reading performance than single-line spacing, and most subjects preferred double line spacing.