Three miles of 10% downgrade with 100 tons of shot rock on your back. The retarder is your best friend until it overheats — then it's nobody's friend. Make the dump. Keep it between the berms.
SPEED0 mph
ZONE LIMIT35 mph
GRADE10%
RETARDER TEMP
ROLLOVER RISK
TIME0 s
CURVE 20
Physics: gravity pulls you to +1.5 mph every second. Holding RETARD slows you ~3 mph/s but heats the retarder; release to cool. Past 85% temp the retarder fades hard. Speed over the zone limit builds rollover risk — max it and you're in the berm. Crawl under 8 mph and the dispatcher docks you. Zones change: watch the signs. Finish fast, finish upright.