The total number of casualties for 2015 was 598, compared to 794 in 2014 and 806 in 1999, the furthest the figures go back.
For 2015, there were four fatal, 74 serious and 490 slight causalities.
The previous year, 2014, had seen seven fatal, 80 serious and 696 slight, while in 2012, there had been 10 fatalities.
“The road casualty figures in North Lincolnshire have reduced significantly over the years,” said Coun Neil Poole, cabinet member for Neighbourhoods at North Lincolnshire Council.
“This is down to the continued hard work of our Road Safety Partnership in North Lincolnshire and working with partners to monitor roads across North Lincolnshire and implement safety measures.
“Speeding and inappropriate speed is one of the most important road safety issues.
“It is a priority to ensure that our roads in North Lincolnshire are safe for both drivers and pedestrians. The speed management strategy plays a major part in this.”
The Road Safety Partnership has a speed management strategy to deal with all speed related concerns.
It targets locations with the highest number of road casualties and worst speed offending rates.
There are more than 400 locations monitored in the speed management strategy, with the top 53 sites targeted with flashing vehicle activated signs, police enforcement, ‘Check your speed’ signs and publicity.