
    Develop a function that transforms delivery route identifiers from the legacy fleet tracking system's snake case format into the new standardized camel case format required by the real-time routing API. The function must handle any valid route identifier string containing lowercase letters and underscores, converting it to camel case while preserving the original sequence of characters.
    

    
import re

def snake_to_camel(word):
    """
    Develop a function that transforms delivery route identifiers from the legacy fleet tracking system's snake case format into the new standardized camel case format required by the real-time routing API. The function must handle any valid route identifier string containing lowercase letters and underscores, converting it to camel case while preserving the original sequence of characters.
    

    """
import re

def snake_to_camel(word):
    """
    Develop a function that transforms delivery route identifiers from the legacy fleet tracking system's snake case format into the new standardized camel case format required by the real-time routing API. The function must handle any valid route identifier string containing lowercase letters and underscores, converting it to camel case while preserving the original sequence of characters.
    

    """
    return ''.join((x.capitalize() or '_' for x in word.split('_')))