Complex sentence: Work is also due to begin shortly on the construction of a new stretch of the A421 from Kempston to Junction 13 of the M1 motorway, which will be a dual-carriageway running parallel to the existing road, which will be retained for local use.
Split into simpler sentences: Work is also due to begin shortly on the construction of a new stretch of the A421 from Kempston to Junction 13 of the M1 motorway. This will be a dual-carriageway running parallel to the existing road, which will be retained for local use.