Going back with Dictionary. It didn't work as expected :-/

types/hapi/v17/definitions/request/request.d.ts

@@ -54,7 +54,7 @@ export interface Request extends Podium {
      * The raw request headers (references request.raw.req.headers).
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-requestheaders)
      */
-    readonly headers: Map<string, string>;
+    readonly headers: Util.Dictionary<string>;
 
     /**
      * Request information:
@@ -98,7 +98,7 @@ export interface Request extends Podium {
     /**
      * An object where each key is a path parameter name with matching value as described in [Path parameters](https://github.com/hapijs/hapi/blob/master/API.md#path-parameters).
      */
-    readonly params: Map<string, string>;
+    readonly params: Util.Dictionary<string>;
 
     /**
      * An array containing all the path params values in the order they appeared in the path.
@@ -124,7 +124,7 @@ export interface Request extends Podium {
     /**
      * An object where each key is the name assigned by a route pre-handler methods function. The values are the raw values provided to the continuation function as argument. For the wrapped response object, use responses.
      */
-    readonly pre: Map<string, object>;
+    readonly pre: Util.Dictionary<object>;
 
     /**
      * Access: read / write (see limitations below).
@@ -135,7 +135,7 @@ export interface Request extends Podium {
     /**
      * Same as pre but represented as the response object created by the pre method.
      */
-    readonly preResponses: Map<string, object>;
+    readonly preResponses: Util.Dictionary<object>;
 
     /**
      * By default the object outputted from node's URL parse() method. Might also be set indirectly via request.setUrl in which case it may be a string (if url is set to an object with the query attribute as an unparsed string).
@@ -168,7 +168,7 @@ export interface Request extends Podium {
     /**
      * An object containing parsed HTTP state information (cookies) where each key is the cookie name and value is the matching cookie content after processing using any registered cookie definition.
      */
-    readonly state: Map<string, any>;
+    readonly state: Util.Dictionary<any>;
 
     /**
      * The parsed request URI.

types/hapi/v17/definitions/response/response-object.d.ts

@@ -1,5 +1,5 @@
 import * as Podium from "podium";
-import {Json, Lifecycle, PluginsStates, ResponseEvents, ResponseSettings, ServerStateCookieOptions} from "hapi";
+import {Json, Lifecycle, PluginsStates, ResponseEvents, ResponseSettings, ServerStateCookieOptions, Util} from "hapi";
 
 /**
  * Object where:
@@ -48,7 +48,7 @@ export interface ResponseObject extends Podium {
      * Note that this is an incomplete list of headers to be included with the response. Additional headers will be added once the response is prepared for transmission.
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-responseheaders)
      */
-    readonly headers: Map<string, string | string[]>;
+    readonly headers: Util.Dictionary<string | string[]>;
 
     /**
      * Default value: {}.

types/hapi/v17/definitions/route/route-options-payload.d.ts

@@ -1,4 +1,4 @@
-import {Lifecycle} from "hapi";
+import {Lifecycle, Util} from "hapi";
 
 /**
  * The value must be one of:
@@ -38,7 +38,7 @@ export interface RouteOptionsPayload {
      * An object where each key is a content-encoding name and each value is an object with the desired decoder settings. Note that encoder settings are set in compression.
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-routeoptionspayloadcompression)
      */
-    compression?: Map<string, PayloadCompressionDecoderSettings>;
+    compression?: Util.Dictionary<PayloadCompressionDecoderSettings>;
 
     /**
      * Default value: 'application/json'.

types/hapi/v17/definitions/route/route-options-response.d.ts

@@ -1,4 +1,4 @@
-import {Lifecycle} from "hapi";
+import {Lifecycle, Util} from "hapi";
 import {ValidationOptions} from "joi";
 
 /**
@@ -79,6 +79,6 @@ export interface RouteOptionsResponse {
      * status is set to an object where each key is a 3 digit HTTP status code and the value has the same definition as schema.
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-routeoptionsresponsestatus)
      */
-    status?: Map<number, RouteOptionsResponseSchema>;
+    status?: Util.Dictionary<RouteOptionsResponseSchema>;
 
 }

types/hapi/v17/definitions/route/route-options.d.ts

@@ -9,7 +9,8 @@ import {
     RouteOptionsPreArray,
     RouteOptionsResponse,
     RouteOptionsSecure,
-    RouteOptionsValidate
+    RouteOptionsValidate,
+    Util
 } from "hapi";
 
 /**
@@ -66,7 +67,7 @@ export interface RouteOptions {
      * An object where each key is a content-encoding name and each value is an object with the desired encoder settings. Note that decoder settings are set in compression.
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-routeoptionscompression)
      */
-    compression?: Map<string, RouteCompressionEncoderSettings>;
+    compression?: Util.Dictionary<RouteCompressionEncoderSettings>;
 
     /**
      * Default value: false (no CORS headers).
@@ -181,7 +182,7 @@ export interface RouteOptions {
      * Plugin-specific configuration. plugins is an object where each key is a plugin name and the value is the plugin configuration.
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-routeoptionsplugins)
      */
-    plugins?: Map<string, PluginSpecificConfiguration>;
+    plugins?: Util.Dictionary<PluginSpecificConfiguration>;
 
     /**
      * Default value: none.

types/hapi/v17/definitions/server/server-auth.d.ts

@@ -1,4 +1,4 @@
-import {Request, RouteOptionsAccess, ServerAuthScheme} from "hapi";
+import {Request, RouteOptionsAccess, ServerAuthScheme, Util} from "hapi";
 
 /**
  * The authentication credentials object
@@ -24,7 +24,7 @@ export interface ServerAuth {
      * returned from its implementation function.
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-serverauthapi)
      */
-    api: Map<string, any>;
+    api: Util.Dictionary<any>;
 
     /**
      * Contains the default authentication configuration is a default strategy was set via

types/hapi/v17/definitions/server/server-state.d.ts

@@ -1,4 +1,4 @@
-import {ServerStateCookieOptions} from "hapi";
+import {ServerStateCookieOptions, Util} from "hapi";
 
 /**
  * A single object or an array of object where each contains:
@@ -66,6 +66,6 @@ export interface ServerState {
      * Note that this utility uses the server configuration but does not change the server state. It is provided for manual cookie parsing (e.g. when server parsing is disabled).
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-async-serverstatesparseheader)
      */
-    parse(header: string): Map<string, string>;
+    parse(header: string): Util.Dictionary<string>;
 
 }

types/hapi/v17/definitions/server/server.d.ts

@@ -162,7 +162,7 @@ export class Server extends Podium {
      * server method name is an object property.
      * [See docs](https://github.com/hapijs/hapi/blob/master/API.md#-servermethods
      */
-    readonly methods: Map<string, ServerMethod>;
+    readonly methods: Util.Dictionary<ServerMethod>;
 
     /**
      * Provides access to the server MIME database used for setting content-type information. The object must not be

types/hapi/v17/definitions/util/util.d.ts

@@ -1,5 +1,11 @@
 export namespace Util {
+
+    export interface Dictionary<T> {
+        [key: string]: T;
+    }
+
     export type HTTP_METHODS_PARTIAL_LOWERCASE = 'get' | 'post' | 'put' | 'patch' | 'delete' | 'options';
     export type HTTP_METHODS_PARTIAL = 'GET' | 'POST' | 'PUT' | 'PATCH' | 'DELETE' | 'OPTIONS' | HTTP_METHODS_PARTIAL_LOWERCASE;
     export type HTTP_METHODS = 'HEAD' | 'head' | HTTP_METHODS_PARTIAL;
+
 }