Judging by the number of people who drive down my suburban residential street at more than 30 miles / hour, and who habitually accelerate rapidly and then brake heavily before each turn, the price of fuel hasn't gone up at all enough to start changing behaviour among individuals. The same driving style is still in evidence on the motorway too.
Road hauliers, bus and train companies, and other fleet managers are probably feeling the sting in so far as they are not contracted for fuel at previous lower rates. They are already very keen on maximising fuel efficiency.
Medium term the other thing people might be able to do is downgrade the size or engine capacity of their car, or if they have the cash, upgrade to a newer, more efficient model. Again not really any evidence of this happening.
I'm sure the price will rise still further through the rest of this year. Fuel at many service stations is already up to £1.99 / litre.