The village is roughly 170 m above sea level, fairly flat except to the west where there is a valley with theMauldre river which runs from the area calledla Maison Blanche to the north.
Coignières is connected byroute nationale 10 (RN10), which traverses the commune from the northeast to the southwest, and given the amount of traffic it effectively divides the commune in two. Coignières train station is located on theParis–Chartres train line and runs parallel to the RN10.
The commune is quite well developed with new housing and commercial zones nearMaurepas and beyond theSaint-Quentin-en-Yvelines region. There is also a large industrial zone (le Marais) between the RN10 and the railway line.
Part of the commune to the west is still a partly wooded rural area (Bois des Hautes Bruyères).
Finally, theGR 11 footpath also cuts across the commune from east to west.
There are two preschools and elementary schools, École Gabriel Bouvet and ÉcoleMarcel Pagnol, as well as one junior high school, Collège d'Enseignement Secondaire « La Mare aux Saules ».[4]