While Regulations define the when of curb use, a Rule defines the who, what, and why. Rules can also specify other conditions (such as required payment or time limits) that impact the use of the curb.

If a Rule does not specify a who field, it will be assumed to apply to all curb users. A given Regulation can have multiple Rules associated with it, but only one of those Rules can have an empty who. When evaluating what Rule applies to a specific UserClass, the Rule without a who will be considered the default if no other rules apply to the user.

A rule may be written as a prohibition (e.g. "No Parking") or as an authorization (e.g. "Loading Zone"). CurbSpec can indicate what rule is in effect at a given place and time (or that no rule is in effect), but local regulation will determine what specific activities are allowed under any particular rule. For example, local rules may allow for passenger loading in a "No Parking" zone but not in a "No Stopping" zone.

Definition

field	format	description	example
rule	string	Indicates what is being allowed or prohibited by the rule. This is the primary use policy and should not include details about time or user-specific restrictions.	Parking or No Stopping or Taxi Stand
reason	string	An optional human-readable explanation that adds context to the rule (e.g. the why).	Street Cleaning or Construction Zone
who	object	A UserClass object that defines who the rule applies to. If not specified, rule will be assumed to apply to all users.
time_limit	integer	Defines the length of time (in minutes) the curb may be used under this rule	120 (2 hours)
payment	string (values: yes or no)	Indicates whether payment is required	yes

Examples

Simple rule

Defines a No Stopping rule that applies to all road users.

{
  rule: "No Stopping"
}

Resident parking

Defines a rule to allow people with a Zone 4 Resident Parking Permit to park.

{
  rule: "Parking",
  reason: "Resident Only Parking"
  who: {
    class: "Resident Permit",
    subclass: "Zone 4"
  }
}

Time-limited handicap space

Allows parking for handicap users with a 3 hour time limit.

{
  rule: "Parking",
  who: {
    class: "Handicap"
  },
  time_limit: 180
}

Meter parking with time limit

Anyone may park for up to two hours with payment

{
  rule: "Parking",
  time_limit: 120,
  payment: "yes"
}