The efforts of Taylor, who finished on 204 not out and Shahzad, who fell for 77, enabled the home county to reach 478 for eight , at which point Chris Read declared, leaving the two sides to shake hands.
With more 100 overs lost to the weather during the first two days, a stalemate always seemed likely but it was guaranteed as the two batsmen batted throughout the first half of the day and combined in a seventh-wicket stand of 200, the fifth-highest in the county's history.
The pair had come together on the third evening with Notts on 199 for six in the 66th over, still 158 away from avoiding the follow-on. They had some anxious moments before reaching the safety mark, just after lunch. Taylor had been dropped on eight the previous day and Shahzad also gave an opportunity at a similarly early stage of his innings.
Pushing forward at Monty Panesar, he gave a bat pad chance to Michael Yardy, which went to ground. On 42 he was also put down by Lewis Hatchett, 15 yards in at fine leg, also off the same bowler.
Shahzad was the very definition of concentration, taking a stroll out towards the square leg umpire after each delivery. His highest career score of 88 had come against Sussex at Hove in 2009, during his days as a Yorkshire player - and his only previous Nottinghamshire fifty had come on the same ground when the sides met three weeks ago.
A first century seemed likely until Shahzad punched Chris Jordan to Matt Machan at point. The Barbadian fast bowler, who claimed nine wickets when the sides met at Hove, gained his fourth five-wicket haul of the summer to strengthen his position as the leading wicket-taker in Division One.
Luke Fletcher made 14 and Andre Adams hit a typically robust 28 not out, featuring two huge sixes, as the game petered out towards its conclusion. The last roar from the crowd greeted Taylor's double hundred, arriving from 357 balls faced and including 21 boundaries.
Taylor's innings surpassed his previous best for Notts - an innings of 163 not out against Sussex last year, which concluded at the same time as he was being announced in the England Test side for the first time.
Fifth-placed Nottinghamshire earned eight points from their fourth consecutive draw, whilst Sussex remain unbeaten and move up to second after collecting 10 points.