In the 19th century the trade on the road began to decline probably due to better transport by river and canal, particularly the rivers Ivel and Ouse from Biggleswade to Kings Lynn and the Lea from Ware to London. The arrival of the railway in 1850 further decreased the traffic on the Great North Road and the trade which depended on it.
In addition the brewing trade lost its preference for the brown malt of Hertfordshire so the demand for malt in places like London declined dramatically. Baldock lost some of its hustle and bustle as trade declined but still retained some importance in the age of the motor car, both as a stop on the A1 main road and as the point where Londoners turned east for Cambridge, Newmarket races, Norwich and the east coast holiday resorts.