head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Pure Mechanics
Arcade racing with Mario Kart-style power-ups bolted onto licensed cars.

Execution · Practiced Mastery
A kart racer testing driving precision and item management on user-created tracks.
Blur leans Execution (Pure Mechanics); ModNation Racers: Road Trip leans Execution (Practiced Mastery).
Blur leans a little harder on execution, though the gap is small.
Blur
Racing lines and dodging shots demand car control
ModNation Racers: Road Trip
Drifting and boosting at speed demands driving precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Blur
Human racers bait and time power-ups against you
ModNation Racers: Road Trip
Versus humans, anticipating weapon use matters somewhat
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Blur
Power-up pickups and incoming attacks add chaos
ModNation Racers: Road Trip
Item pickups and weapon spread add kart-racer chaos
ModNation Racers: Road Trip leans a little harder on optimization, though the gap is small.
Blur
Track knowledge and pickup routes are learnable
ModNation Racers: Road Trip
Track lines, boost management and shortcuts reward planning
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.