diff --git a/R/create.R b/R/create.R
index d9d45992d..d3e8bedc6 100644
--- a/R/create.R
+++ b/R/create.R
@@ -273,7 +273,8 @@ create_rt_data <- function(rt = rt_opts(), breakpoints = NULL,
     rt <- rt_opts(
       use_rt = FALSE,
       future = "project",
-      gp_on = "R0"
+      gp_on = "R0",
+      rw = 0
     )
   }
   # define future Rt arguments
@@ -283,6 +284,10 @@ create_rt_data <- function(rt = rt_opts(), breakpoints = NULL,
   )
   # apply random walk
   if (rt$rw != 0) {
+    if (is.null(breakpoints)) {
+      stop("breakpoints must be supplied when using random walk")
+    }
+
     breakpoints <- seq_along(breakpoints)
     breakpoints <- floor(breakpoints / rt$rw)
     if (!(rt$future == "project")) {
@@ -292,11 +297,12 @@ create_rt_data <- function(rt = rt_opts(), breakpoints = NULL,
       }
     }
   }else {
-    if (is.null(breakpoints) || sum(breakpoints) == 0) {
-      rt$use_breakpoints <- FALSE
-    }
     breakpoints <- cumsum(breakpoints)
   }
+
+  if (sum(breakpoints) == 0) {
+    rt$use_breakpoints <- FALSE
+  }
   # add a shift for 0 effect in breakpoints
   breakpoints <- breakpoints + 1
 
diff --git a/tests/testthat/test-create_rt_date.R b/tests/testthat/test-create_rt_date.R
new file mode 100644
index 000000000..748ae80d4
--- /dev/null
+++ b/tests/testthat/test-create_rt_date.R
@@ -0,0 +1,88 @@
+test_that("create_rt_data returns expected default values", {
+  result <- create_rt_data()
+  
+  expect_type(result, "list")
+  expect_equal(result$r_mean, 1)
+  expect_equal(result$r_sd, 1)
+  expect_equal(result$estimate_r, 1)
+  expect_equal(result$bp_n, 0)
+  expect_equal(result$breakpoints, numeric(0))
+  expect_equal(result$future_fixed, 1)
+  expect_equal(result$fixed_from, 0)
+  expect_equal(result$pop, 0)
+  expect_equal(result$stationary, 0)
+  expect_equal(result$future_time, 0)
+})
+
+test_that("create_rt_data handles NULL rt input correctly", {
+  result <- create_rt_data(rt = NULL)
+  
+  expect_equal(result$estimate_r, 0)
+  expect_equal(result$future_fixed, 0)
+  expect_equal(result$stationary, 1)
+})
+
+test_that("create_rt_data handles custom rt_opts correctly", {
+  custom_rt <- rt_opts(
+    prior = list(mean = 2, sd = 0.5),
+    use_rt = FALSE,
+    rw = 0,
+    use_breakpoints = FALSE,
+    future = "project",
+    gp_on = "R0",
+    pop = 1000000
+  )
+  
+  result <- create_rt_data(rt = custom_rt, horizon = 7)
+  
+  expect_equal(result$r_mean, 2)
+  expect_equal(result$r_sd, 0.5)
+  expect_equal(result$estimate_r, 0)
+  expect_equal(result$pop, 1000000)
+  expect_equal(result$stationary, 1)
+  expect_equal(result$future_time, 7)
+})
+
+test_that("create_rt_data handles breakpoints correctly", {
+  result <- create_rt_data(rt_opts(use_breakpoints = TRUE), 
+                           breakpoints = c(1, 0, 1, 0, 1))
+  
+  expect_equal(result$bp_n, 3)
+  expect_equal(result$breakpoints, c(2, 2, 3, 3, 4))
+})
+
+test_that("create_rt_data handles random walk correctly", {
+  result <- create_rt_data(rt_opts(rw = 2), 
+                           breakpoints = rep(1, 10))
+  
+  expect_equal(result$bp_n, 5)
+  expect_equal(result$breakpoints, c(1, 2, 2, 3, 3, 4, 4, 5, 5, 6))
+})
+
+test_that("create_rt_data throws error for invalid inputs", {
+  expect_error(create_rt_data(rt_opts(rw = 2)),
+               "breakpoints must be supplied when using random walk")
+})
+
+test_that("create_rt_data handles future projections correctly", {
+  result <- create_rt_data(rt_opts(future = "project"), horizon = 7)
+  
+  expect_equal(result$future_fixed, 0)
+  expect_equal(result$fixed_from, 0)
+  expect_equal(result$future_time, 7)
+})
+
+test_that("create_rt_data handles zero sum breakpoints", {
+  result <- create_rt_data(rt_opts(use_breakpoints = TRUE), 
+                           breakpoints = rep(0, 5))
+  
+  expect_equal(result$bp_n, 0)
+})
+
+test_that("create_rt_data adjusts breakpoints for horizon", {
+  result <- create_rt_data(rt_opts(rw = 2, future = "latest"), 
+                           breakpoints = rep(1, 10),
+                           horizon = 3)
+  
+  expect_equal(result$breakpoints, c(1, 2, 2, 3, 3, 4, 4, 4, 4, 4))
+})